Adhesive composition comprising amorphous propylene-ethylene copolymer and polyolefins

ABSTRACT

Amorphous propylene-ethylene copolymers are described herein that can include high amounts of ethylene and exhibit desirable softening points and needle penetrations. The desirable combinations of softening points and needle penetrations in these propylene-ethylene copolymers allow them to have a broad operating window. Due their broad operating window, the propylene-ethylene copolymers can be utilized in a wide array of applications and products, including hot melt adhesives.

CROSS REFERENCES TO RELATED APPLICATIONS

This is application claims priority to U.S. Provisional Application No.62/517,255 filed on Jun. 9, 2017, and is a continuation-in-partapplication claiming priority to U.S. application Ser. No. 15/443,278filed on Feb. 27, 2017 (now U.S. Pat. No. 10,214,600), which claimspriority to U.S. application Ser. No. 14/567,028 filed on Dec. 11, 2014(now U.S. Pat. No. 9,611,341), which claims priority to U.S. ProvisionalApplication No. 61/937,024 filed on Feb. 7, 2014, and this applicationis also a continuation-in-part application claiming priority to U.S.application Ser. No. 15/683,964 filed on Aug. 23, 2017 (now U.S Pat. No.10,308,740), which claims priority to U.S. Provisional Application No.62/378,698 filed on Aug. 24, 2016; the disclosures of which are hereinincorporated by reference in their entireties.

BACKGROUND

1. Field of the Invention

The present invention is generally related to amorphouspropylene-ethylene copolymers and processes for producing suchcopolymers. Particularly, the present invention is generally related toamorphous propylene-ethylene copolymers having desirable needlepenetrations, softening points, crystallinity, viscosities, andviscoelastic characteristics. More particularly, the present inventionis related to low molecular weight amorphous propylene-ethylenecopolymers that can be utilized in adhesive compositions having a wideprocess window and high peel strengths especially in hygieneapplications.

2. Description of the Related Art

Amorphous polyolefins are commonly used in industry to produce a widearray of products including, for example, adhesives. Common polyolefinsutilized in adhesives generally include copolymers produced frompropylene, ethylene, and various C₄-C₁₀ alpha-olefin monomers, such as,for example, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene,1-nonene, and 1-decene. In particular, propylene-butene copolymers arecommonly used to produce hot melt adhesives due to the higher adhesivebond strengths derived from these copolymers. Much of the adhesive bondstrength derived from these copolymers can be attributed to the C₄-C₁₀alpha-olefins contained therein, which can greatly increase thesubsequent bonding properties of the copolymer. Unfortunately, C₄-C₁₀alpha-olefins can be quite expensive due to market availability and canalso exhibit limited reactivity during the polymerization processes.

Due to the above deficiencies of the C₄-C₁₀ alpha-olefins, somemanufacturers have attempted to replace C₄-C₁₀ alpha-olefins withethylene. Unlike many of the C₄-C₁₀ alpha-olefins, ethylene can be morereadily available and more reactive than many of the commonly usedC₄-C₁₀ alpha-olefins, such as 1-butene. Unfortunately,propylene-ethylene copolymers can exhibit deficiencies in hardness,thereby resulting in adhesives that lack ideal bond strength over time.Some manufacturers have attempted to increase the hardness of thesecopolymers by incorporating crystalline polypropylene therein. However,by adding crystalline polypropylene to these copolymers, the softeningpoints of the copolymers are also increased. This can limit theapplication of these copolymers to certain types of adhesives due to thehigher softening points.

Thus, there is a need for amorphous copolymers that exhibit an idealbalance between hardness and softening point and that can also be usedto produce adhesives with improved adhesive characteristics.

In addition, this invention also involves a low molecular weightamorphous propylene-ethylene copolymers that can be utilized in adhesivecompositions having a wide process window and high peel strengthsespecially in hygiene applications. The need for high peel strength ismotivated by concerns for safety for the hygiene user, especially forthe diaper user. Lower peel strength could lead to premature failure ofthe bond lines holding the various elements of the diaper construction,and subsequently expose the diaper user to the superabsorbent material.Another concern related to low peel strength is the local bond failurethat would lead, upon insult of the diaper, to the channeling of thebody fluid with a resulting reduction of the overall protection of thediaper wearer.

Various attempts to emulate the performance of styrene/isoprene/styrenepolymer (SIS) and styrene-butadiene-styrene polymer adhesiveformulations have been made. The introduction to the hygiene industry ofmore complex styrenic copolymers(styrene-ethylene-ethylene-propylene-styrene (SEEPS),styrene-isoprene-butylene-styrene (SIBS), styrene-ethylene-butylene(SEB), styrene-ethylene-butylene-styrene (SEBS),styrene-ethylene-propylene-styrene (SEPS), andstyrene-butylene-butylene-styrene (SBBS)), various other thermoplasticrubbers, chain shuttling catalyzed olefin block copolymer (OBC), andamorphous poly alpha olefins (APAO) are examples of such efforts. Theuse of metallocene-catalyzed olefins has also been documented.Nevertheless, the attempts fell short of achieving the goal of producinga simple formulation that yields a wide process window simultaneouslycoupled with high peel strength. Therefore, there is a need for such apolymer that can provide these attributes in an adhesive formulation.

SUMMARY

One or more embodiments of the present invention concern a copolymercomprising propylene and ethylene, which has a softening point in therange of 90 to 140° C. Furthermore, the copolymer has a needlepenetration that is equal to y, which is defined by the followingformula:y≤−0.000000262249x ⁶+0.000172031278x ⁵−0.046669720165x ⁴+6.701746779438x³−537.286013331959x ²+22,802.983472587x−400,204.018086126.In the above formula, x is the softening point of the copolymer.

Additionally, one or more embodiments of the present invention concern acopolymer comprising propylene and ethylene. The copolymer has asoftening point in the range of 110 to 135° C. and a needle penetrationof less than 25 dmm.

Furthermore, one or more embodiments of the present invention concern acopolymer comprising propylene and ethylene. The copolymer has asoftening point in the range of 90 to 121° C. and a needle penetrationof less than 35 dmm.

Also, one or more embodiments of the present invention concern acopolymer comprising propylene and ethylene. The copolymer has asoftening point in the range of 90 to less than 115° C. and a needlepenetration equal to or less than 53 dmm.

Also, one or more embodiments of the present invention concerns a lowmolecular copolymer comprising propylene and ethylene. The low molecularweight copolymer has a softening point in the range of 90 to 140° C. Thelow molecular weight copolymer has a needle penetration that is equal toy, wherein y is defined by the following formula:y≤−0.000000262249x ⁶+0.000172031278x ⁵−0.046669720165x ⁴+6.701746779438x³−537.286013331959x ²+22,802.983472587x−400,204.018086126,wherein x in the above formula is the softening point of the copolymer;wherein the low molecular weight copolymer has a molecular weightpolydispersibility index of about 3 to about 25, a crystallinity ofabout 18% to about 30% by X-Ray diffraction, and a Brookfield viscosityin the range of about 1,000 to about 4,000 cp at 190° C. measured byASTM D 3236.

Moreover, one or more embodiments of the present invention concern a hotmelt adhesive. The hot melt adhesive comprises a copolymer comprisingpropylene and ethylene. The copolymer has a softening point in the rangeof 90 to 140° C. and a needle penetration that is equal to y, which isdefined by the following formula:y≤−0.000000262249x ⁶+0.000172031278x ⁵−0.046669720165x ⁴+6.701746779438x³−537.286013331959x ²+22,802.983472587x−400,204.018086126.In the above formula, x is the softening point of the copolymer.

In addition, one or more embodiments of the present invention concern aprocess for producing a copolymer. The process comprises reactingpropylene and ethylene in the presence of a catalyst system comprisingan electron donor to form the copolymer. The copolymer has a softeningpoint in the range of 90 to 140° C. and a needle penetration that isequal to y, which is defined by the following formula:y≤−0.000000262249x ⁶+0.000172031278x ⁵−0.046669720165x ⁴+6.701746779438x³−537.286013331959x ²+22,802.983472587x−400,204.018086126In the above formula, x is the softening point of the copolymer.

In yet further embodiments of the present invention, a process forproducing a copolymer is provided. The process comprises reactingpropylene and ethylene in the presence of a catalyst system comprisingan electron donor to form the copolymer. The copolymer has a softeningpoint in the range of 110 to 140° C. and a needle penetration that isequal to y, which is defined by the following formula:y≤−0.000751414552642x ⁴+0.374053308337937x ³−69.5967657676062x²+5,734.02599677759x−176,398.494888882.In the above formula, x is the softening point of the copolymer.

One or more embodiments of the present invention concern an adhesivecomposition comprising at least one propylene-ethylene copolymer and atleast one propylene polymer, wherein the propylene-ethylene copolymercomprises at least 10 weight percent of ethylene and a softening pointof at least 99° C.

One or more embodiments of the present invention concern an adhesivecomposition comprising at least one propylene-ethylene copolymer and atleast one propylene polymer, wherein the propylene-ethylene copolymercomprises a polydispersity of at least 3.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments of the present invention are described herein with referenceto the following drawing figures, wherein:

FIG. 1A depicts the viscoelastic characteristics of particularpropylene-ethylene copolymers produced in Example 1;

FIG. 1B depicts the viscoelastic characteristics of particularpropylene-ethylene copolymers produced in Example 1;

FIG. 2 depicts the viscoelastic characteristics of the adhesivesproduced in Example 4;

FIG. 3 depicts the viscoelastic characteristics of the adhesive producedin Example 5;

FIG. 4 depicts the viscoelastic characteristics of the adhesivesproduced in Example 6;

FIG. 5 depicts the viscoelastic properties as a function of temperaturefor comparative Aerafin® 180 copolymer;

FIG. 6 depicts the viscoelastic properties as a function of temperatureof the inventive low molecular weight copolymer;

FIG. 7 depicts the capillary rheometry for the inventive low molecularweight copolymer and comparative Aeratin® 180 copolymer;

FIG. 8. depicts the experimental layout for molecular weight;

FIG. 9. depicts the peel strength performance for adhesive compositionsfor various molecular weight distributions;

FIG. 10 depicts the peel strength as a function of the inventive lowmolecular weight copolymer content in various adhesive formulations; and

FIGS. 11-20 depict the peel strengths versus spray temperatures ofadhesive compositions containing the inventive low molecular weightcopolymer as well as comparative data.

DETAILED DESCRIPTION

The present invention is generally related to amorphouspropylene-ethylene copolymers and their various applications. Many ofthe existing propylene-ethylene copolymers in the market today generallyexhibit deficiencies regarding their softening points or hardness. Theinventive copolymers described herein exhibit improved propertiescurrently not available in these commercial copolymers. In particular,as described below in further detail, the inventive copolymers canexhibit desirable softening points and needle penetrations, therebyresulting in copolymers that are useful in a wide array of applications.Furthermore, the inventive low molecular weight copolymers provideadditional features including a wide operating window for adhesiveapplications and also high peel strengths.

The Propylene-Ethylene Copolymers

Commercially-available propylene-ethylene copolymers have generally notbeen strong enough to be used in adhesives for packaging applications orhygiene products (e.g., diapers and feminine care products). Generally,this has to do with the lack of balance between the strength andadhesion properties of the copolymers. Historically, in order to producea copolymer with sufficient strength, one had to limit the ethylenecontent of the copolymer. It has been observed that there is acorrelation between the ethylene contents of a copolymer and itssoftening point and needle penetration, which is an indication of thecopolymer's strength. Usually, the ethylene content can have a negativecorrelation with the softening point of the copolymer and a positivecorrelation with the needle penetration of the copolymer. In otherwords, the more ethylene that is present in a copolymer, the lower thesoftening point and higher the needle penetration of the copolymer.Thus, increasing the ethylene content in a propylene-ethylene copolymermay decrease the copolymer's softening point, but can also compromiseits strength as shown by an increased needle penetration.

Unlike conventional propylene-ethylene copolymers available today, theinventive copolymers can exhibit a desirable softening point and needlepenetration with relatively high ethylene contents. As previously noted,it can be desirable to utilize ethylene as a comonomer in propylenecopolymers due to the high availability and low costs of ethylenecompared to other alpha-olefins. Furthermore, there can bepolymerization advantages in using ethylene as a comonomer sinceethylene can be much more reactive than many other alpha-olefins.

According to various embodiments, the propylene-ethylene copolymersdescribed herein can comprise varying amounts of ethylene. For example,the propylene-ethylene copolymers can comprise at least 1, 3, 5, 7, 10,12, 14, 15, 17, 18, or 20 and/or not more than 70, 65, 60, 55, 50, 45,40, 35, 30, 27, or 25 weight percent of ethylene. Moreover, thepropylene-ethylene copolymers can comprise in the range of 1 to 70, 3 to65, 5 to 60, 7 to 55, 10 to 50, 12 to 45, 14 to 40, 15 to 35, 17 to 30,18 to 27, or 20 to 25 weight percent of ethylene.

Furthermore, in various embodiments, the propylene-ethylene copolymerscan contain varying amounts of propylene. For example, thepropylene-ethylene copolymers can comprise at least 40, 50, 60, 65, or70 and/or not more than 99, 95, 90, 85, or 80 weight percent ofpropylene. Moreover, the propylene-ethylene copolymers can comprise inthe range of 40 to 99, 50 to 95, 60 to 90, 65 to 85, or 70 to 80 weightpercent of propylene.

In various embodiments, the copolymers can comprise at least 50, 65, 75,or 85 and/or not more than 99, 97.5, 95, or 90 weight percent ofethylene and propylene in combination. Moreover, the copolymers cancomprise in the range of 50 to 99, 65 to 97.5, 75 to 95, or 85 to 90weight percent ethylene and propylene in combination. Additionally oralternatively, the copolymers can comprise a weight ratio of propyleneto ethylene of at least 0.5:1, 1:1, 2:1, or 2.5:1 and/or not more than20:1, 15:1, 10:1, or 5:1. Moreover, the copolymers can comprise a weightratio of propylene to ethylene in the range of 0.5:1 to 20:1, 1:1 to15:1, 2:1 to 10:1, or 2.5:1 to 5:1.

In various embodiments, the copolymers can contain one or more C₄-C₁₀alpha-olefins. As previously noted, C₄-C₁₀ alpha-olefins can be used toincrease the resulting bond strength of the copolymers when utilized inadhesives. These C₄-C₁₀ alpha-olefins can include, for example,1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene,and combinations thereof. According to one or more embodiments, thecopolymers can comprise at least 0.5, 1, 2, 3, 4, or 5 and/or not morethan 40, 30, 25, 20, 15, or 10 weight percent of at least one C₄-C₁₀alpha-olefin. Moreover, the copolymers can comprise in the range of 0.5to 40, 1 to 30, 2 to 25, 3 to 20, 4 to 15, or 5 to 10 weight percent ofat least one C₄-C₁₀ alpha-olefin.

As noted above, a lower softening point for the copolymers can bedesirable so that the copolymers can be utilized and processed at lowerapplication temperatures. In various embodiments, the copolymers canhave a softening point of at least 85, 90, 95, 96, 97, 98, 99, 100, 101,102, 103, 104, 105, 106, 107, 108, 109, 110, 113, 115, 116, 119, 120,121, 124, 125, or 127° C. Additionally or alternatively, the copolymerscan have a softening point of not more than 145, 140, 138, 137, 136,135, 134, 132, 130, 129, 128, 127, 126, 125, 124, 123, 122, 121, 120,118, 117, 115, 110, or 109.9° C. as measured according to ASTM E28Standard Test Method for Softening Point of Resins Derived from PineChemicals and Hydrocarbons, by Ring-and Ball Apparatus using a heatingrate of 5° C. per minute and a bath liquid of USP Glycerin.

Moreover, the copolymers can have a softening point in the range of 85to 145° C., 90 to 140° C., 90 to 110° C., 90 to 121° C., 90 to 115° C.,95 to 138° C., 95 to 110° C., 96 to 136° C., 97 to 135° C., 98 to 134°C., 99 to 132° C., 100 to 130° C., 101 to 129° C., 102 to 128° C., 103to 127° C., 104 to 126° C., 105 to 125° C., 106 to 124° C., 107 to 123°C., 108 to 122° C., 109 to 121° C., or 110 to 120° C. as measuredaccording to ASTM E28 as discussed previously.

Despite exhibiting the low softening points described above, thecopolymers can also exhibit desirable needle penetration values.Generally, the lower the needle penetration value, the higher thestrength characteristics and modulus of the copolymer; however, if theneedle penetration gets too low, then adhesive properties can beadversely impacted. In various embodiments, when the softening point isin the range of 90 to 140° C., the needle penetration values of thecopolymers described herein can be defined by the following formula:

y≤−0.000000262249x⁶+0.000172031278x⁵−0.046669720165x⁴+6.701746779438x³−537.286013331959x²+22,802.983472587x−400,204.018086126.In the above formula, “y” defines the needle penetration (dmm) of thecopolymer and “x” is the softening point (° C.) of the copolymer.

Needle penetration is measured following the ASTM D5 Standard TestMethod for Penetration of Bituminous Materials and utilizing thefollowing specifications:

-   -   The weight of the spindle is 47.5+/−0.05 g.    -   The weight of the ferrule needle assembly is 2.50+/−0.05 g.    -   The total weight of the needle and spindle assembly is        50.0+/−0.05 g.    -   A weight of 50+/−0.05 g shall also be provided for total load of        100 g.    -   Samples are conditioned in a water bath at temperature of        25+/−0.1° C. [77+/−0.2° F.]    -   The time the needle penetrates into the sample is 5+/−0.1 s

In various other embodiments, when the softening point is in the rangeof 110 to 140° C., the needle penetration values of the copolymersdescribed herein can be defined by the following formula:y≤−0.000751414552642x ⁴+0.374053308337937x ³−69.5967657676062x²+5,734.02599677759x−176,398.494888882.In the above formula, “y” defines the needle penetration (dmm) of thecopolymer and “x” is the softening point (° C.) of the copolymer.

In various embodiments, the copolymers can have a needle penetration ofat least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 20, 30, or 35decimillimeters (“dmm”) as measured according to ASTM D5 as discussedpreviously. Additionally or alternatively, the copolymers can have aneedle penetration of not more than 75, 73.8, 70, 60, 50, 45, 40, 30,29, 28, 27, 26, 25, 24, 23, 22, 21, 20, or 15 dmm as measured accordingto ASTM D5 as discussed previously. Moreover, the copolymers can have aneedle penetration in the range of 1 to 75, 2 to 50, 3 to 30, 4 to 29, 5to 28, 6 to 27, 7 to 26, 8 to 25, 9 to 24, 10 to 23, 11 to 22, 12 to 21,or 13 to 20 dmm as measured according to ASTM D5 as discussedpreviously.

Depending on their intended end use, the copolymers can have varyingsoftening points and needle penetration ranges. In various embodiments,the copolymers can have a softening point in the range of 90 to 121° C.and needle penetration less than 35 dmm. In other embodiments, thecopolymers can have a softening point in the range of 90 to 115° C. anda needle penetration of less than 53 dmm. In various embodiments, thecopolymers can have a softening point in the range of 110 to 138° C. andneedle penetration in the range of 1 to 15 dmm. Furthermore, in certainembodiments, the copolymers can have a softening point in the range of110 to 135° C. and needle penetration in the range of 5 to 15 dmm.Moreover, in certain embodiments, the copolymers can have a softeningpoint in the range of 110 to 130° C. and needle penetration in the rangeof 10 to 15 dmm.

In various embodiments, the copolymers can have a softening point in therange of 110 to 137° C. and needle penetration in the range of 1 to 22dmm. Furthermore, in certain embodiments, the copolymers can have asoftening point in the range of 110 to 135° C. and needle penetration inthe range of 5 to 22 dmm. In other embodiments, the copolymers can havea softening point in the range of 110 to 135° C. and needle penetrationin the range of 10 to 24 dmm. Moreover, in certain embodiments, thecopolymers can have a softening point in the range of 110 to 130° C. andneedle penetration in the range of 10 to 20 dmm.

In various embodiments, the copolymers can have a softening point in therange of 110 to 134° C. and needle penetration in the range of 1 to 25dmm. Furthermore, in certain embodiments, the copolymers can have asoftening point in the range of 110 to 132° C. and needle penetration inthe range of 5 to 25 dmm. Moreover, in certain embodiments, thecopolymers can have a softening point in the range of 110 to 130° C. andneedle penetration in the range of 10 to 25 dmm.

In various embodiments, the copolymers can have a softening point in therange of 110 to 124° C. and needle penetration in the range of 1 to 30dmm. Furthermore, in certain embodiments, the copolymers can have asoftening point in the range of 110 to 122° C. and needle penetration inthe range of 5 to 30 dmm. Moreover, in certain embodiments, thecopolymers can have a softening point in the range of 110 to 120° C. andneedle penetration in the range of 10 to 30 dmm.

In various embodiments, the copolymers can have a softening point in therange of 110 to 120° C. and needle penetration in the range of 30 to 50dmm. Furthermore, in certain embodiments, the copolymers can have asoftening point in the range of 110 to 120° C. and needle penetration inthe range of 35 to 50 dmm. Moreover, in certain embodiments, thecopolymers can have a softening point in the range of 110 to 120° C. andneedle penetration in the range of 30 to 45 dmm.

In various embodiments, the copolymers can have a softening point in therange of 90 to 125° C. and needle penetration of less than 30 dmm.Furthermore, in certain embodiments, the copolymers can have a softeningpoint in the range of 90 to 123° C. and needle penetration of less than35 dmm. Moreover, in certain embodiments, the copolymers can have asoftening point in the range of 90 to 125° C. and needle penetration inthe range of 10 to 30 dmm.

In various embodiments, the copolymers can have a softening point in therange of 90 to 109.9° C. and needle penetration of less than 73.8 dmm.Furthermore, in certain embodiments, the copolymers can have a softeningpoint in the range of 127 to 140° C. and needle penetration of less than25 dmm. Moreover, in certain embodiments, the copolymers can have asoftening point in the range of 124 to 126° C. and needle penetration ofless than 30 dmm.

In various embodiments, the copolymers can have a softening point in therange of 121 to 123° C. and needle penetration of less than 40 dmm.Furthermore, in certain embodiments, the copolymers can have a softeningpoint in the range of 119 to 120° C. and needle penetration of less than50 dmm. Moreover, in certain embodiments, the copolymers can have asoftening point in the range of 116 to 118° C. and needle penetration ofless than 60 dmm. In other embodiments, the copolymers can have asoftening point in the range of 113 to 117° C. and needle penetration ofless than 70 dmm.

Generally, lower softening points in the copolymers can sometimes beaccompanied by lower glass transition (“Tg”) temperatures. In variousembodiments, the copolymers can have a glass transition temperature ofat least −100, −80, −60, or −40 and/or not more than about 20, 0, −10,or −20° C. as measured according to DMA. Moreover, the copolymers canhave a Tg in the range of −100 to 20° C., −80 to 0° C., −60 to −10° C.,or −40 to −20° C. as measured according to DMA.

Furthermore, in various embodiments, the copolymers can have a meltviscosity at 190° C. of at least 100, 500, 1,000, 3,000, or 5,000 and/ornot more than about 100,000, 75,000, 50,000, 35,000, or 25,000 cP asmeasured according to ASTM D3236. Moreover, the copolymers can have amelt viscosity at 190° C. in the range of 100 to 100,000, 500 to 75,000,1,000 to 50,000, 3,000 to 35,000, or 5,000 to 25,000 cP as measuredaccording to ASTM D3236.

According to one or more embodiments, the copolymers can have aBrookfield viscosity at 190° C. of at least 100, 300, 500, or 750 and/ornot more than 30,000, 10,000, 5,000, or 2,500 cps as measured accordingto ASTM D3236. Moreover, the copolymers can have a Brookfield viscosityat 190° C. in the range of 100 to 30,000, 300 to 10,000, 500 to 5,000,or 750 to 2,500 cps.

In one or more embodiments, the copolymers described herein can alsohave a number average molecular weight (Mn) of less than 100,000,50,000, or 25,000 as determined by gel permeation chromatography.

In various embodiments, the copolymers described herein do not exhibitsubstantial changes in color when subjected to storage conditions atelevated temperatures over extended periods of time. Before any agingdue to storage occurs, the inventive copolymers can have an initialGardner color of less than 4, 3, 2, or 1 as measured according to ASTMD1544. After being heat aged at 177° C. for at least 96 hours, theinventive copolymers can exhibit a final Gardner color of less than 7,5, 3, or 2 as measured according to ASTM D1544. Thus, the inventivecopolymers can retain a desirable color even after prolonged storage andexposure.

Additionally, the copolymers described herein can be amorphous orsemi-crystalline. As used herein, “amorphous” means that the copolymershave a crystallinity of less than 5 percent as measured usingDifferential Scanning calorimetry (“DSC”) according to ASTM E 794-85. Asused herein, “semi-crystalline” means that the copolymers have acrystallinity in the range of 5 to 40 percent as measured using DSCaccording to ASTM E 794-85. In various embodiments, the copolymers canhave a crystallinity of not more than 60, 40, 30, 20, 10, 5, 4, 3, 2, or1 percent as measured using DSC according to ASTM E 794-85.

Low Molecular Weight Propylene-Ethylene Copolymers

In various embodiments of the present invention, the inventivepropylene-ethylene copolymers can comprise low molecular weightpropylene-ethylene copolymers. These low molecular weightpropylene-ethylene copolymers can comprise any of the characteristicsand properties described above in regard to the propylene-ethylenecopolymers and are described below in greater detail.

In various embodiments of the present invention, a copolymer is providedcomprising propylene and ethylene and that has a softening point in therange of 90 to 140° C. Furthermore, the copolymer can have a needlepenetration that is equal to y, wherein y is defined by the followingformula:

y≤−0.000000262249x⁶+0.000172031278x⁵−0.046669720165x⁴+6.701746779438x³−537.286013331959x²+22,802.983472587x−400,204.018086126,wherein “x” in the above formula is the softening point of thecopolymer. Moreover, the copolymer can have a molecular weightpolydispersibility of about 3 to about 25, a crystallinity of about 18to about 30 percent as measured by X-ray Diffraction, and a Brookfieldviscosity of about 1,000 to about 4,000 cP at 190° C. as measured byASTM D3236.

This inventive low molecular weight copolymer can be utilized to producepolyolefin-based hot melt adhesives for use in the manufacture oflaminated items. The adhesive comprising the low molecular weightcopolymer may also be used to make personal care hygiene articles suchas baby and adult incontinence diapers, pads, and feminine napkins. Thehot melt adhesives of this invention yield both a wide process windowduring manufacturing of laminated structures and high peel strength,despite the low molecular weight of the polyolefin used. The hot meltadhesives of this invention can yield a substantially consistent peelstrength for the laminates across the wide process window.

Also, surprisingly, despite the relatively high softening point andcrystallinity of the inventive low molecular weight copolymer as opposedto the softening point and crystallinity of comparative polymers, hotmelt adhesive composition containing the inventive low molecular weightcopolymer can be easily applied at lower temperature. The adhesiveformulations containing the inventive low molecular weight copolymer maybe applied using various spray nozzles and slot dies at temperaturesranging from about 120 to about 160° C. Other ranges are from about 130to about 160° C. and from about 130 to about 150° C. and at variousmachine speeds from 100 to 600 m/min.

Certain properties of the low molecular weight copolymer are measuredper the procedures outlined in Examples 14-16. Otherwise, the testmethods listed in this specification are utilized.

In various embodiments, the low molecular weight propylene-ethylenecopolymer can have a weight average molecular weight (Mw) ranging fromabout 25,000 to about 50,000. Other exemplary ranges for Mw are fromabout 30,000 to about 45,000 and about 35,000 to about 40,000. In otherembodiments, the number average molecular weight (Mn) of the lowmolecular weight propylene-ethylene copolymer can range from about 1,000to about 20,000. Other exemplary ranges are from about 1,500 to about16,000, about 2,000 to about 15,000, and 2,500 to 14,000. In yet otherembodiments, the z-average molecular weight (Mz) of the low molecularweight propylene-ethylene copolymer can range from about 80,000 to about140,000. Other exemplary ranges for Mz are from about 85,000 to about130,000, about 90,000 to about 120,000, and about 100,000 to about120,000. The molecular weights (Mn, Mw, and Mz) of the low molecularweight copolymer can be measured per the procedures outlined in Examples14-16.

In various embodiments, the polydispersibility (Mw/Mn) of the lowmolecular weight propylene-ethylene copolymer can range from about 3 toabout 25, from about 4 to about 24, from about 5 to about 20, from about6 to about 15, and from about 8 to about 10. In various embodiments, thelow molecular weight propylene-ethylene copolymer can have apolydispersibility of at least 3, 4, 5, 6, 7, or 8 and/or not more than25, 24, 20, 15, or 10.

In various embodiments, the glass transition (Tg) of the low molecularweight propylene-ethylene copolymer can range from about −45 to about−30° C.

In various embodiments, the melt temperature (Tm) of the low molecularweight propylene-ethylene copolymer can range from about 90 to about138° C., from about 100 to about 135° C., and from about 120 to about130° C.

In various embodiments, the melt energy ΔHm (J/g) of the low molecularweight propylene-ethylene copolymer can be less than 15 J/g.

In various embodiments, the crystallinity of the low molecular weightpropylene-ethylene copolymer can range from about 18 to about 30 percentas measured by X-ray diffraction. Other exemplary ranges ofcrystallinity include from about 20 to about 30 percent, from about 22to about 28 percent, and about 22 to about 26 percent.

In various embodiments, the crystallization temperature (Tc) of the lowmolecular weight propylene-ethylene copolymer can range from about 50 toabout 110° C., from about 60 to about 80° C., and from about 50 to about70° C.

In various embodiments, the crystallization energy (ΔHc) of the lowmolecular weight propylene-ethylene copolymer can be less than 20 J/g,less than 15 J/g, or less than 10 J/g.

In various embodiments, the Brookfield Viscosity at 190° C. of the lowmolecular weight propylene-ethylene copolymer can range from about 1,000cP to about 4,000 cP, from about 1,200 cP to about 3,600 cP, and fromabout 1,500 cP to about 3,000 cP.

In various embodiments, the storage modulus (G′) of the low molecularweight propylene-ethylene copolymer at 25° C. can range from about 1 MPaand 10 MPa, from about 2 MPa to about 8 MPa, and from about 3 MPa toabout 5 MPa.

In various embodiments, the tensile strength of the low molecular weightpropylene-ethylene copolymer can range from about 2.5 MPa to about 4.5MPa or from about 2.7 MPa to about 3.5 MPa.

In various embodiments, the G′/G″ crossover temperature of the lowmolecular weight propylene-ethylene copolymer can range from about 100to about 120° C. or about 105 to about 110° C.

In various embodiments, the tan δ of the low molecular weightpropylene-ethylene copolymer at the crossover temperature can range fromabout 0.35 to about 0.50 or from about 0.38 to about 0.48.

In various embodiments of the present invention, the low molecularweight propylene-ethylene copolymer has a weight average molecularweight of about 25,000 to about 45,000, a number average molecularweight of about 1,000 to about 12,000, a z-average molecular weight ofabout 90,000 to about 140,000, a polydispersibility (Mw/Mn) of about 3to about 25, a crystallinity of about 20% to about 30%, and a Brookfieldviscosity of 1,000 to 4,000 cP at 190° C. Additional exemplarycharacteristics of the low molecular weight propylene-ethylene copolymerfor use in the formulations of this invention include storage modulus(G′ at 25° C.) of 1 to 10 MPa; a crossover temperature (for G′ and G″)of 110 to 120° C. with an associated tan δ of 0.35 to 0.50; and a glasstransition of −40 to −25° C.

The Processes for Producing the Propylene-Ethylene Copolymers

In various embodiments, the copolymers can be produced by reactingpropylene monomers and ethylene monomers in the presence of a catalystsystem comprising at least one electron donor.

In various embodiments, the catalyst system can comprise a Ziegler-Nattacatalyst. According to one or more embodiments, the Ziegler-Nattacatalyst can contain a titanium-containing component, an aluminumcomponent, and an electron donor. In certain embodiments, the catalystcomprises titanium chloride on a magnesium chloride support.

The catalyst systems, in certain embodiments, can comprise aheterogeneous-supported catalyst system formed from titanium compoundsin combination with organoaluminum co-catalysts. In various embodiments,the co-catalyst can comprise an alkyl aluminum co-catalyst (“TEAL”).

In one or more embodiments, the catalyst system can have an aluminum totitanium molar ratio of at least 1:1, 5:1, 10:1, or 15:1 and/or not morethan 100:1, 50:1, 35:1, or 25:1. Moreover, the catalyst system can havean aluminum to titanium molar ratio in the range of 1:1 to 100:1, 5:1 to50:1, 10:1 to 35:1, or 15:1 to 25:1. Additionally or alternatively, invarious embodiments, the catalyst system can have a molar ratio ofaluminum to silicon of at least 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, or 6:1and/or not more than 100:1, 50:1, 35:1, 20:1, 15:1, 10:1, or 8:1.Moreover, the catalyst system can have a molar ratio of aluminum tosilicon in the range of 0.5:1 to 100:1, 1:1 to 50:1, 2:1 to 35:1, 2:1 to20:1, 2:1 to 15:1, 2:1 to 10:1, or 2:1 to 8:1.

Electron donors are capable of increasing the copolymer'sstereospecificity. However, it can be important to closely regulate thecontents of the electron donors since they can suppress catalystactivity to unacceptable levels in some circumstances. The electrondonors used during the polymerization process can include, for example,organic esters, ethers, alcohols, amines, ketones, phenols, phosphines,and/or organosilanes. Furthermore, the catalyst system can compriseinternal donors and/or external donors.

In various embodiments, the catalyst system comprises at least oneexternal electron donor. In one or more embodiments, the externalelectron donor comprises at least one alkoxy silane. In particular, incertain embodiments, the alkoxy silane can comprisedicyclopentyldimethoxysilane, cyclohexylmethyldimethoxysilane, or acombination thereof. Moreover, in some embodiments, the alkoxy silanecan comprise, consist essentially of, or consist entirely ofdicyclopentyldimethoxysilane.

It has been observed that the addition of the above external donors tothe catalyst system can increase the hardness (i.e., decrease the needlepenetration) and viscosities of the copolymers. However, contrary towhat has been previously observed in the art, the electron donorsdescribed above can actually lower the softening points of the producedcopolymers instead of increasing it. Furthermore, it has been observedthat substantially all (i.e., greater than 95 percent) of the ethyleneadded to the reactor during the polymerization process can react whenthe above electron donors are used. Thus, this can result in copolymershaving higher ethylene contents and lower propylene contents.Consequently, when using the above electron donors, propylene-ethylenecopolymers can be produced that have higher ethylene contents, but stillexhibit desired balances between softening point and hardness.

In addition, according to various embodiments, the catalyst system canhave a molar ratio of electron donor to titanium of at least 0.1:1,0.5:1, 1:1, 1.25:1, 1.5:1, or 2:1 and/or not more than 20:1, 15:1, 10:1,5:1, 4.5:1, or 4:1. Moreover, the catalyst system can have a molar ratioof electron donor to titanium in the range of 0.1:1 to 20:1, 0.5:1 to15:1, 1:1 to 10:1, 1.25:1 to 5:1, 1.5:1 to 4.5:1, or 2:1 to 4:1.Additionally or alternatively, in various embodiments, the catalystsystem can comprise a molar ratio of TEAL co-catalyst to the electrondonor of at least 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, or 6:1 and/or not morethan 100:1, 50:1, 35:1, 20:1, 15:1, 10:1, or 8:1. Moreover, the catalystsystem can comprise a molar ratio of TEAL co-catalyst to the electrondonor in the range of 0.5:1 to 100:1, 1:1 to 50:1, 2:1 to 35:1, 2:1 to20:1, 2:1 to 15:1, 2:1 to 10:1, or 2:1 to 8:1. In certain embodiments,the type of electron donor can influence the necessary TEAL/electrondonor ratio. For instance, in embodiments where the electron donor isdicyclopentyldimethoxysilane, the TEAL/electron donor ratio can be lessthan 20:1.

The catalyst system can exhibit a catalyst activity in the range of 200to 2,000, 400 to 1,200, or 500 to 1,000 g/g. Catalyst activity iscalculated by measuring the ratio of the weight the polymer made in thereactor to the weight of the catalyst charged into the reactor. Thesemeasurements are based on a reaction time of one hour.

Since the addition of external donors can increase viscosity andmolecular weight, the addition of hydrogen can be required to act as achain terminator during polymerization. For example, the process can becarried out at a hydrogen pressure in the range of 5 to 100, 10 to 80,or 15 to 50 psig.

In various embodiments, the polymerization reaction can occur at atemperature in the range of 100 to 200, 110 to 180, or 120 to 150° C.Furthermore, the polymerization reaction can be carried out a pressurein the range of 500 to 2,000, 700 to 1,500, or 800 to 1,250 psig.

In certain embodiments, the reactor can comprise a stirred reactor andthe polymerization reaction can have a residence time in the reactor inthe range of 0.1 to 6, 0.5 to 4, or 1 to 2 hours. In variousembodiments, the ethylene can be added to the reactor as a gas and thepropylene can be added as a liquid.

End Products Incorporating the Propylene-Ethylene Copolymers

The inventive propylene-ethylene copolymers described herein andcompositions comprising these copolymers can be utilized in a wide arrayof applications including, for example, adhesives, sealants, caulks,roofing membranes, waterproof membranes and underlayments, carpet,laminates, laminated articles, tapes (e.g., tamper evident tapes, wateractivated tapes, gummed tape, sealing tape, scrim reinforced tape,veneer tape, reinforced and non-reinforced gummed paper tape, box makerstape, paper tape, packaging tape, HVAC duct tape, masking tape,invisible tape, electrical tape, gaffer tape, hockey tape, medical tape,etc.), labels (e.g., general purpose label, beverage label, freezerlabel, smart label, consumer electronics etc.), mastics, polymer blends,wire coatings, molded articles, heat seal coatings, disposable hygienearticles, insulating glass (IG) units, bridge decking, water proofingmembranes, waterproofing compounds, underlayments, cableflooding/filling compounds, sheet molded compounds, dough moldedcompounds, overmolded compounds, rubber compounds, polyester composites,glass composites, fiberglass reinforced plastics, wood-plasticcomposites, polyacrylic blended compounds, lost-wax precision castings,investment casting wax compositions, candles, windows, films, gaskets,seals, o-rings, motor vehicle molded parts, motor vehicle extrudedparts, clothing articles, rubber additive/processing aids, and fibers.

Films comprising the inventive propylene-ethylene copolymer describedherein and compositions comprising these copolymers include, but are notlimited to, multilayer films, coextruded films, calendared films, andcast films. Laminates comprising the inventive propylene-ethylenepolymer or compositions comprising the inventive propylene-ethylenepolymer include, but are not limited to, paper-foil laminates,paper-film laminates, and nonwoven-film laminates.

Adhesive compositions comprising the inventive propylene-ethylenecopolymer described herein and compositions comprising these copolymersinclude packaging adhesives, food contact grade adhesives, indirect foodcontact packaging adhesives, product assembly adhesives, woodworkingadhesives, flooring adhesives, automotive assembly adhesives, structuraladhesives, mattress adhesives, pressure sensitive adhesives (PSA), PSAtapes, PSA labels, PSA protective films, self-adhesive films, laminatingadhesives, flexible packaging adhesives, heat seal adhesives, industrialadhesives, hygiene nonwoven construction adhesives, hygiene coreintegrity adhesives, and hygiene elastic attachment adhesives.

In certain embodiments, the copolymers described herein can be utilizedin adhesives, such as, for example, hot melt adhesives, water basedadhesives, solvent-based adhesives, hot melt pressure-sensitiveadhesives, solvent-based pressure-sensitive adhesives, hot meltnonwoven/hygiene adhesives, hot melt product assembly adhesives, hotmelt wood working adhesives, and hot melt packaging adhesives. Inparticular, due to their unique combination of softening point andneedle penetration as previously described, adhesives produced from theinventive copolymers can be utilized in a vast array of end products,including hygienic packaging and other packaging applications. In manyembodiments, the various properties of the inventive copolymers, such assoftening point and needle penetration, can be selected to suit theintended end use of the composition incorporating the copolymers.

In certain embodiments, the inventive copolymers can be used to produceadhesives useful for packaging, product assembly, film laminating, woodworking, and/or profile wrapping.

In various embodiments, the adhesives of the present invention comprisehot melt adhesives. Hot melt adhesives can be applied to a substratewhile in its molten state and cooled to harden the adhesive layer. Suchadhesives are widely used for various commercial and industrialapplications such as product assembly and packaging. In theseapplications, adhesive is applied to at least one substrate for bindingthe substrate to a second similar or different substrate.

Adhesive formulators and users generally want thermally stable, lowcolor hot melt adhesives with favorable balance of physical properties,including temperature resistance, chemical resistance, cohesivestrength, viscosity, adhesion to a variety of substrates, and open andset times that can be tailored to the particular use and applicationconditions. The balance of desired properties varies with theapplication, and the inventive hot melt compositions described hereinprovide an improved balance of properties for multiple end uses.

The hot melt adhesive compositions can have melt rheology and thermalstability suitable for use with conventional hot melt adhesiveapplication equipment. In various embodiments, the blended components ofthe hot melt adhesive compositions have low melt viscosity at theapplication temperature, thereby facilitating flow of the compositionsthrough a coating apparatus, e.g., coating die or nozzle.

The hot melt adhesive composition is useful for bonding a variety ofsubstrates including, e.g., cardboard, coated cardboard, paperboard,fiber board, virgin and recycled kraft, high and low density kraft,chipboard, treated and coated kraft and chipboard, and corrugatedversions of the same, clay coated chipboard carton stock, composites,leather, polymer film (e.g., polyolefin films (e.g., polyethylene andpolypropylene), polyvinylidene chloride films, ethylene vinyl acetatefilms, polyester films, metalized polymer film, multilayer film, andcombinations thereof), fibers and substrates made from fibers (e.g.,virgin fibers, recycled fibers, synthetic polymer fibers, cellulosefibers, and combinations thereof), release liners, porous substrates(e.g., woven webs, nonwoven webs, nonwoven scrims, and perforatedfilms), cellulose substrates, sheets (e.g., paper, and fiber sheets),paper products, tape backings, and combinations thereof. Usefulcomposites include, e.g., chipboard laminated to metal foil (e.g.,aluminum foil), which optionally can be laminated to at least one layerof polymer film, chipboard bonded to film, Kraft bonded to film (e.g.,polyethylene film), and combinations thereof.

The hot melt adhesive composition is useful in bonding a first substrateto a second substrate in a variety of applications and constructionsincluding, e.g., packaging, bags, boxes, cartons, cases, trays,multi-wall bags, articles that include attachments (e.g., strawsattached to drink boxes), ream wrap, cigarettes (e.g., plug wrap),filters (e.g., pleated filters and filter frames), bookbinding,footwear, disposable absorbent articles (e.g., disposable diapers,sanitary napkins, medical dressings (e.g., wound care products),

bandages, surgical pads, drapes, gowns, and meat-packing products),paper products including, e.g., paper towels (e.g., multiple usetowels), toilet paper, facial tissue, wipes, tissues, towels (e.g.,paper towels), sheets, mattress covers, and components of absorbentarticles including, e.g., an absorbent element, absorbent cores,impermeable layers (e.g., backsheets), tissue (e.g., wrapping tissue),acquisition layers and woven and nonwoven web layers (e.g., top sheets,absorbent tissue), and combinations thereof.

The hot melt adhesive composition is also useful in forming laminates ofporous substrates and polymer films such as those used in themanufacture of disposable articles including, e.g., medical drapes,medical gowns, sheets, feminine hygiene articles, diapers, adultincontinence articles, absorbent pads for animals (e.g., pet pads) andhumans (e.g., bodies and corpses), and combinations thereof.

The hot melt adhesive composition can be applied to a substrate in anyuseful form including, e.g., as fibers, as a coating (e.g., a continuouscoatings and discontinuous coatings (e.g., random, pattern, and array)),as a bead, as a film (e.g., a continuous films and discontinuous films),and combinations thereof, using any suitable application methodincluding, e.g., slot coating, spray coating (e.g., spiral spray, randomspraying, and random fiberization (e.g., melt blowing)), foaming,extrusion (e.g., applying a bead, fine line extrusion, single screwextrusion, and twin screw extrusion), wheel application, noncontactcoating, contacting coating, gravure, engraved roller, roll coating,transfer coating, screen printing, flexographic, and combinationsthereof.

Typical, but non-limiting, industrial applications of the hot meltadhesive compositions include packaging, particularly for lowtemperature uses such as for dairy products or for freezer packaging offood products, and in sanitary disposable consumer articles, forexample, diapers, feminine care pads, napkins, etc. Traditional end useapplications such as book-binding, wood working and labeling will alsobenefit from both the low temperature flexibility, heat resistance, andthe efficiency of end use in automated means of applying the hot meltadhesive compositions to various substrates.

Furthermore, in various embodiments, the inventive copolymers describedherein can also be used to modify existing polymer blends that aretypically utilized in plastics, elastomeric applications, roofingapplications, cable filling, and tire modifications. The inventivecopolymers can improve the adhesion, processability, stability,viscoelasticity, thermal properties, and mechanical properties of thesepolymer blends.

In various embodiments, the inventive propylene-ethylene copolymers canbe modified to produce graft copolymers. In such embodiments, theinventive copolymers can be grafted with maleic anhydride, fumarate andmaleate esters, methacrylate esters (e.g., glycidyl methacrylate andhydroxethyl methacrylate), methacrylic acid, vinyl derivatives, silanederivatives, or combinations thereof. These graft copolymers can beproduced using any conventional process known in the art including, forexample, transesterification and free radical induced coupling.

The various end uses and end products noted above can utilize theinventive copolymer by itself or can combine it with other additives andpolymers. Suitable polymers that can be combined with the inventivecopolymers to form a polymer blend may include, for example,isoprene-based block copolymers; butadiene-based block copolymers;hydrogenated block copolymers; ethylene vinyl acetate copolymers;polyesters; polyester-based copolymers; neoprenes; urethanes; acrylics;polyacrylates; acrylate copolymers, such as, but not limited to,ethylene acrylic acid copolymer, ethylene n-butyl acrylate copolymers,and ethylene methyl acrylate copolymers; polyether ether ketones;polyamides; styrenic block copolymers; hydrogenated styrenic blockcopolymers; random styrenic copolymers; ethylene-propylene rubbers;ethylene vinyl acetate copolymers; butyl rubbers; styrene butadienerubbers; butadiene acrylonitrile rubbers; natural rubbers;polyisoprenes; polyisobutylenes; polyvinyl acetates; and polyolefins.

Polyolefins used with the inventive propylene-ethylene copolymers inthis invention can be any that is known in the art. In one embodiment ofthe invention, the polyolefins can be at least one selected from thegroup consisting of amorphous polyolefins, semi-crystalline polyolefins,alpha-polyolefins, reactor-ready polyolefins, metallocene-catalyzedpolyolefin polymers and elastomers, reactor-made thermoplasticpolyolefin elastomers, olefin block copolymers, thermoplasticpolyolefins, atactic polypropylene, polyethylenes, ethylene-propylenepolymers, propylene-hexene polymers, ethylene-butene polymers,ethylene-octene polymers, propylene-butene polymers, propylene-octenepolymers, metallocene-catalyzed polypropylene polymers,metallocene-catalyzed polyethylene polymers, propylene-based terpolymersincluding ethylene-propylene-butylene terpolymers, copolymers producedfrom propylene and linear or branched C₄-C₁₀ alpha-olefin monomers,copolymers produced from ethylene and linear or branched C₄-C₁₀alpha-olefin monomers, and functionalized polyolefins.

Multiple methods exist in the art for functionalizing polymers that maybe used with the polymers described here. These include selectiveoxidation, free radical grafting, ozonolysis, epoxidation, and the like.Functionalized components include, but are not limited to,functionalized olefin polymers, (such as functionalized C₂ to C₄₀homopolymers, functionalized C₂ to C₄₀ copolymers, functionalized higherMw waxes), functionalized oligomers (such as functionalized low Mwwaxes, functionalized tackifiers), beta nucleating agents, andcombinations thereof. Functionalized olefin polymers and copolymersuseful in this invention include maleated polyethylene, maleatedmetallocene polyethylene, maleated metallocene polypropylene, maleatedethylene propylene rubber, maleated polypropylene, maleated ethylenecopolymers, functionalized polyisobutylene (typically functionalizedwith maleic anhydride typically to form a succinic anhydride), and thelike.

In various embodiments, the inventive propylene-ethylene copolymersdescribed herein can be used to produce a hot melt adhesive. Accordingto one or more embodiments, the adhesives can comprise at least 1, 5,10, 15, 20, 25, 30, 35, 40, or 45 and/or not more than 95, 90, 80, 70,60, 55, 50, 45, 40, 35, 30, 25, 20, 15, or 10 weight percent of theinventive copolymer. Moreover, the adhesives can comprise in the rangeof 1 to 95, 5 to 90, 10 to 80, 20 to 70, 30 to 60, or 40 to 55 weightpercent of the inventive copolymers. In certain embodiments, theadhesive can be entirely comprised of the inventive copolymer.

Furthermore, depending on the intended end use, these hot melt adhesivescan also comprise various additives including, for example, polymers,tackifiers, processing oils, waxes, antioxidants, plasticizers,pigments, and fillers.

In various embodiments, the adhesives can comprise at least 10, 20, 30,or 40 and/or not more than 90, 80, 70, or 55 weight percent of at leastone polymer that is different from the inventive copolymers. Moreover,the adhesives can comprise in the range of 10 to 90, 20 to 80, 30 to 70,or 40 to 55 weight percent of at least one polymer that is differentfrom the inventive copolymers. These polymers can include any of thepolymers listed above.

Furthermore, it has been discovered that blends of the inventivecopolymers with various types of polyolefins may provide adhesives withimproved adhesion, cohesive strength, temperature resistance, viscosity,and open and set times. Thus, in various embodiments, theabove-described polymers that may be combined with the inventivepropylene-ethylene copolymers can comprise at least one polyolefin. Incertain embodiments, the adhesives can comprise at least 1, 5, 10, 15,20, 25, 30, 35, 40, 45, or 50 weight percent of at least one polyolefinin addition to the above-described propylene-ethylene copolymer.Additionally or alternatively, the adhesives can comprise not more than99, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15,10, or 5 weight percent of at least one polyolefin in addition to theabove-described propylene-ethylene copolymer. For example, the adhesivescan comprise in the range of 1 to 90, 1 to 60, 1 to 40, 1 to 20, 10 to90, 20 to 80, 20 to 40, 30 to 70, 30 to 40, or 40 to 55 weight percentof at least one polyolefin. In one or more embodiments, thesepolyolefins can be amorphous polyolefins having a heat of fusion lessthan 25 J/g or less than 15 J/g.

Commercial examples of acceptable amorphous polyolefins include Aerafin™17 by Eastman Chemical; Aerafin™ 180 by Eastman Chemical, Rextac™polymers made by REXtac LLC including Rextac™ E-63, E-65, 2760, 2815,and 2830; Vestoplast, including Vestoplast® 408 and 708; and Eastoflex®by Eastman Chemical, including Eastoflex® E1060 and P1010.

Some examples of metallocene-catalyzed polymers include polyolefins suchas polyethylene, polypropylene, and copolymers thereof such aspolypropylene-based elastomers sold by ExxonMobil Chemical under thetrade name VISTAMAXX™ and polyethylene-based elastomers such as thosesold by Dow Chemical Company under the trade names AFFINITY™ andENGAGE™. Other metallocene-catalyzed polymers include the polyolefinelastomers VISTAMAXX™ 8816, VISTAMAXX™ 2230, and ENGAGE™ 8200. AFFINITY™GA 1900 has a density of 0.870 g/cm3 according to ASTM D792, a heat offusion of 46.1 J/g, and a Brookfield viscosity of 8,200 cP at 177° C.according to ASTM D1084. AFFINITY™ GA 1950 has a density of 0.874 g/cm3according to ASTM D792, a heat of fusion of 53.4 J/g, and a Brookfieldviscosity of 17,000 cP at 177° C. according to ASTM D1084. ENGAGE™ 8200has a density of 0.87 g/cm3 according to ASTM D792 and a melt index of 5g/10 min at 190° C. These polyolefin elastomers are compatible with theinventive copolymers when used in hot melt adhesives.

In one embodiment of the invention, the inventive propylene-ethylenecopolymer can be utilized with at least one high propylene-contentpolymer to produce compositions useful as adhesives. As used herein,high-propylene content polymer are polymers comprising at least 60 molepercent propylene monomer. In other embodiments of the invention, thehigh-propylene content polymers comprise at least 65, 70, 75, 80, 85,90, 95 mol % propylene monomer. In another embodiment, thehigh-propylene content polymer is a homopolymer of propylene.High-propylene polymers can be any that is known in the art includinghomopolymer, copolymer, terpolymers, and propylene waxes. Other monomersutilized include linear or branched C₂-C₂₀ olefins. “Wax” as used inthis disclosure is defined as a polymer or an oligomer having a heat offusion greater than 50 Joules per gram and a viscosity no greater than750 centipoise (CP) at 190° C.

Examples of high propylene-content polymers include, but are not limitedto, propylene homopolymers; metallocene-catalyzed polypropylenes;propylene-ethylene copolymers; metallocene-catalyzed propylene-ethylenecopolymers; copolymers of propylene and a linear or branched C₄ to C₂₀olefin; a metallocene-catalyzed copolymer of propylene and a linear orbranched C₄ to C₂₀ olefin, terpolymers of propylene, ethylene, and a C₄to C₂₀ olefin; propylene waxes, terpolymers formed from ethylene,propylene, and a diene (EPDM), or a combination thereof.

Suitable high propylene-content polymers are commercially availableunder a variety of trade designations including but not limited to,e.g., the L-MODU series of trade designations sold by Idemitsu KosanCo., Ltd (Japan) including, e.g., L-MODU™ S400, S600, and S900, theVISTAMAXX™ series and ACHIEVE™ series of trade designations sold byExxonMobil Chemical Company (Houston, Tex.) including, e.g., VISTAMAXX™8880 and ACHIEVE™ 6936; also the polymers LICOCENE™ 2602 and 6502 soldby Clariant Intl Ltd. (Muttenz, Switzerland), and EASTMAN G-3015 byEastman Chemical Company. Examples of suitable highpolypropylene-content waxes are commercially available under a varietyof trade designations including but not limited to, e.g., EPOLENE N15from Westlake Chemical Corporation (Houston, Tex.), HONEYWELL A-C® 1089and A-C® 596 from Honeywell Intl Inc. (Morristown, N.J.), and LICOCENE™6102 and MA6252 from Clariant.

In various embodiments, olefin polymers include a mixture of at leasttwo different olefin polymers, e.g., a blend that includes an olefinhomopolymer and an olefin copolymer, a blend that includes differentolefin homopolymers of the same or different monomer, a blend thatincludes different olefin copolymers, and various combinations thereof.Useful olefin polymers also include, e.g., modified, unmodified,grafted, and ungrafted olefin polymers, uni-modal olefin polymers,multi-modal olefin polymers, and combinations thereof.

In various embodiments of the invention, the propylene polymerpreferably includes at least 50 mole %, at least about 60 mole %, atleast about 70 mole %, at least about 80 mole %, at least about 90 mole%, at least about 95 mole %, or even from about 50 mole % to about 100mole % propylene. The propylene polymer optionally includes at least 2mole %, at least about 5 mole %, at least about 10 mole %, at leastabout 20 mole %, at least about 30 mole %, no greater than about 50 mole%, or even from about 20 mole % to about 50 mole % of at least onealpha-olefin co-monomer.

In various embodiments, these added polyolefins can increase thecohesive strength, adhesion properties, tackiness, low temperatureflexibility, total crystallinity, and/or temperature resistance of theinventive adhesives. Furthermore, the addition of the aforementionedpolyolefins may decrease the production costs of the adhesives due totheir widespread availability.

In certain embodiments, the adhesives can comprise the above-describedpropylene-ethylene copolymer and a metallocene-catalyzed polyethylenecopolymer, e.g. an ethylene-octene copolymer. In such embodiments, theinventive propylene-ethylene copolymer can be used to replace thepolyethylene in various types of adhesives, such as those used forpackaging applications.

In certain embodiments, the added polymer and/or polyolefin can befunctionalized with groups including, but not limited to, silanes, acidanhydride such as maleic anhydride, hydroxyl, ethoxy, epoxy, siloxane,amine, aminesiloxane, carboxy, and acrylates, at the polymer chain endsand/or pendant positions within the polymer.

The additional polymers and polyolefins that can be added to theinventive adhesives may be prepared by a Ziegler-Natta catalyst, asingle site catalyst (metallocene), multiple single site catalysts,non-metallocene heteroaryl catalysts, combinations thereof, or anotherpolymerization means. The additional polymers may comprise a combinationof amorphous, semi-crystalline, random, branched, linear, or blockystructures.

Any conventional polymerization synthesis processes may prepare theadditional polyolefin components. In one or more embodiments, one ormore catalysts, which are typically metallocene catalysts orZeigler-Natta, catalysts, are used for polymerization of an olefinmonomer or monomer mixture. Polymerization methods include highpressure, slurry, gas, bulk, suspension, supercritical, or solutionphase, or a combination thereof. The catalysts can be in the form of ahomogeneous solution, supported, or a combination thereof.Polymerization may be carried out by a continuous, a semi-continuous orbatch process and may include use of chain transfer agents, scavengers,or other such additives as deemed applicable. In one or moreembodiments, the additional polymer is produced in a single or multiplepolymerization zones using a single polymerization catalyst. Metallocene(or heterophase) polymers are typically made using multiple metallocenecatalyst blends that obtain the desired heterophase structure.

In various embodiments, the crystalline content of the added polymers orpolyolefins can increase the cohesive strength of the adhesives.Generally, adhesive formulations based on metallocene polymerizedsemicrystalline copolymers can eventually build sufficient crystallinecontent over time to achieve good cohesive strength in the formulation.

In various embodiments, the adhesives can comprise at least 10, 20, 30,or 40 and/or not more than 90, 80, 70, 55, 50, 45, or 40 weight percentof at least one tackifier. Moreover, the adhesives can comprise in therange of 10 to 90, 20 to 80, 20 to 40, 20 to 30, 30 to 70, or 40 to 55weight percent of at least one tackifer. The tackifier gives tack to theadhesive and may also lower the viscosity of the adhesive. Lowerviscosity can improve application flow characteristics, allowing foreasier processing, lower energy requirements, and lower processingtemperatures. Lower viscosity also helps the adhesive to “wet out,” orto substantially uniformly coat the surface and penetrate the substrate.Tack is required in most adhesive formulations to allow for properjoining of articles prior to solidification of the hot melt adhesive.The desirability and selection of the particular tackifying agent candepend upon the specific types of olefin copolymer and additionalpolymers employed.

Suitable tackifiers can include, for example, cycloaliphatic hydrocarbonresins, C₅ hydrocarbon resins; C₅/C₉ hydrocarbon resins;aromatically-modified C₅ resins; C₉ hydrocarbon resins; pure monomerresins such as copolymers or styrene with alpha-methyl styrene, vinyltoluene, para-methyl styrene, indene, methyl indene, C₅ resins, and C₉resins; terpene resins; terpene phenolic resins; terpene styrene resins;rosin esters; modified rosin esters; liquid resins of fully or partiallyhydrogenated rosins; fully or partially hydrogenated rosin esters; fullyor partially hydrogenated modified rosin resins; fully or partiallyhydrogenated rosin alcohols; fully or partially hydrogenated C₅ resins;fully or partially hydrogenated C₅/C₉ resins; fully or partiallyhydrogenated aromatically-modified C₅ resins; fully or partiallyhydrogenated C₉ resins; fully or partially hydrogenated pure monomerresins; fully or partially hydrogenated C₅/cycloaliphatic resins; fullyor partially hydrogenated C₅/cycloaliphatic/styrene/C₉ resins; fully orpartially hydrogenated cycloaliphatic resins; and combinations thereof.Exemplary commercial hydrocarbon resins include Regalite™ hydrocarbonresins (Eastman Chemical). In certain embodiments, the tackifiers cancomprise functionalized tackifiers.

In various embodiments, the adhesives can comprise at least 1, 2, 5, 8,or 10 and/or not more than 40, 30, 25, 20, or 15 weight percent of atleast one processing oil. Moreover, the adhesives can comprise in therange of 2 to 40, 5 to 30, 8 to 25, or 10 to 20 weight percent of atleast one processing oil. Processing oils can include, for example,mineral oils, naphthenic oils, paraffinic oils, aromatic oils, castoroils, rape seed oil, triglyceride oils, or combinations thereof. As oneskilled in the art would appreciate, processing oils may also includeextender oils, which are commonly used in adhesives. The use of oils inthe adhesives may be desirable if the adhesive is to be used as apressure-sensitive adhesive to produce tapes or labels or as an adhesiveto adhere nonwoven articles. In certain embodiments, the adhesive maynot comprise any processing oils.

In various embodiments, the adhesives can comprise at least 1, 2, 5, 8,or 10 and/or not more than 40, 30, 25, 20, or 15 weight percent of atleast one wax. Moreover, the adhesives can comprise in the range of 1 to40, 5 to 30, 8 to 25, or 10 to 20 weight percent of at least one wax.Waxes serve to reduce the overall viscosity of the adhesive, therebyallowing it to liquefy and allowing for the proper application orcoating of the hot melt adhesive onto an intended substrate. The typeand melting point of a wax, and its compatibility with other componentsof the adhesive composition, control the open time and setting speed ofthe adhesive. Open time is known in the art as being the amount of timefor an adhesive to wet out and bond to a substrate after application.Any conventionally known wax, which is suitable for use in formulatinghot melt adhesives, may be used in the practice of the invention.

In one embodiment of the invention, when the inventivepropylene-ethylene copolymer is utilized with a propylene polymer, whichis a propylene wax, no other wax may be required.

Suitable waxes can include, for example, microcrystalline wax, paraffinwax, waxes produced by Fischer-Tropsch processes, functionalized waxes(maleated, fumerated, or wax with functional groups etc.), polyolefinwaxes, petroleum waxes, polypropylene waxes, polyethylene waxes,ethylene vinyl acetate waxes, and vegetable waxes. The use of waxes inthe adhesives may be desirable if the adhesive is to be used as a hotmelt packaging adhesive.

Non-limiting examples of commercially available waxes that are suitablefor this invention include Sasol® H-1, available from Sasol WaxAmericas, Inc.; A-C™-9 and A-C 810, available from HoneywellInternational Inc.; EPOLENE™ N-15 available from Eastman Chemical; andPOLYWAX™ 400, 850, 1000, and 3000 from Baker Hughes Inc.

Other exemplary waxes include, but are not limited to, Evonik Licocene™PE4201; Westlake EPOLENE™ C-10, EPOLENE™ C-17 and EPOLENE™ C-18; andmicrocrystalline wax Be Square™ 195.

As used herein, “functionalized” is meant that the component is eitherprepared in the presence of a functional group that is incorporated intothe component or is contacted with a functional group, and, optionally,a catalyst, heat, initiator, or free radical source to cause all or partof the functional group (such as maleic acid or maleic anhydride) toincorporate, graft, bond to, physically attach to, and/or chemicallyattach to the polymer.

Exemplary functionalized waxes polymers useful as functionalizedcomponents include those modified with an alcohol, an acid, a ketone, ananhydride, and the like. Commercial functionalized waxes includemaleated polypropylene was available from Chusei under the tradenameMAPP 40; maleated metallocene waxes (such as TP LICOCENE PP1602available from Clariant); maleated polyethylene waxes and maleatedpolypropylene waxes available from Westlake under the tradenames EPOLENEC-16, EPOLENE C-18, EPOLENE E43; EASTMAN G-3003 from Eastman Chemical;maleated polypropylene wax LICOMONT AR 504 available from Clariant;grafted functional polymers available from Dow Chemical Co. under thetradenames AMPLIFY EA 100, AMPLIFY EA 102, AMPLIFY 103, AMPLIFY GR 202,AMPLIFY GR 205, AMPLIFYGR 207, AMPLIFY GR 208, AMPLIFY GR 209, andAMPLIFY VA 200; and CERAMER maleated ethylene polymers available fromBaker Hughes under the tradenames CERAMER 1608, CERAMER 1251, CERAMER67, and CERAMER 24. Useful waxes also include polyethylene andpolypropylene waxes having an Mw of 15,000 of less, preferably from3,000 to 10,000, and a crystallinity of 5 wt % or more, preferably 10weight percent or more, having a functional group content of up to 10weight percent. Additional functionalized polymers that may be used asfunctional components include A-C 575P, A-C 573P, A-C X596A, A-C X596P,A-C X597A, A-C X597P, A-C X950P, A-C X1221, A-C 395A, A-C 395A, A-C1302P, A-C 540, A-C 54A, A-C 629, A-C 629A, A-C 307, and A-C 307Aavailable from Honeywell International Inc.

In certain embodiments, the adhesive may not comprise a wax. Forinstance, the adhesive may comprise less than 10, 5, 4, 3, 2, or 1weight percent of a wax such as, but not limited to, a polyethylene waxand/or a Fischer Tropsch wax.

In various embodiments, the adhesives can comprise at least 0.1, 0.2,0.5, 1, 2, or 3 and/or not more than 20, 10, 8, 5, 1, or 0.5 weightpercent of at least one antioxidant. Moreover, the adhesives cancomprise in the range of 0.1 to 20, 1 to 10, 2 to 8, or 3 to 5 weightpercent of at least one antioxidant.

In various embodiments, the adhesives can comprise at least 0.5, 1, 2,or 3 and/or not more than 20, 10, 8, or 5 weight percent of at least oneplasticizer. Moreover, the adhesives can comprise in the range of 0.5 to20, 1 to 10, 2 to 8, or 3 to 5 weight percent of at least oneplasticizer. Suitable plasticizers can include, for example, olefinoligomers, low molecular weight polyolefins such as liquid polybutylene,polyisobutylene, mineral oils, dibutyl phthalate, dioctyl phthalate,chlorinated paraffins, and phthalate-free plasticizers. Commercialplasticizers can include, for example, BenzoflexlM plasticizers (EastmanChemical); Eastman 168™ (Eastman Chemical); Oppanol® B10 (BASF);REGALREZ 1018 (Eastman Chemical); Calsol 5550 (Calumet Lubricants);Kaydol oil (Chevron); or ParaLux oil (Chevron).

In various embodiments, the adhesives can comprise at least 10, 20, 30,or 40 and/or not more than 90, 80, 70, or 55 weight percent of at leastone filler. Moreover, the adhesives can comprise in the range of 1 to90, 20 to 80, 30 to 70, or 40 to 55 weight percent of at least onefiller. Suitable fillers can include, for example, carbon black, calciumcarbonate, clay, titanium oxide, zinc oxide, or combinations thereof.

The adhesive compositions can be produced using conventional techniquesand equipment. For example, the components of the adhesive compositionmay be blended in a mixer such as a sigma blade mixer, a plasticorder, abrabender mixer, a twin screw extruder, or an in-can blend (pint-cans).In various embodiments, the adhesive may be shaped into a desired form,such as a tape or sheet, by an appropriate technique including, forexample, extrusion, compression molding, calendaring or roll coatingtechniques (e.g., gravure, reverse roll, etc.), curtain coating,slot-die coating, or spray coating.

Furthermore, the adhesive may be applied to a substrate by solventcasting processes or by melting the adhesive and then using conventionalhot melt adhesive application equipment known in the art. Suitablesubstrates can include, for example, nonwoven, textile fabric, paper,glass, plastic, films (Polyethylene, Polypropylene, Polyester etc.), andmetal. Generally, about 0.1 to 100 g/m² of the adhesive composition canbe applied to a substrate.

According to one or more embodiments, the hot melt adhesives can have aBrookfield viscosity at 177° C. of at least 100, 300, 500, 750, or 1,000and/or not more than 30,000, 10,000, 5,000, 4,000, 3,000, or 2,500 cpsas measured according to ASTM D3236. Moreover, the hot melt adhesivescan have a Brookfield viscosity at 177° C. in the range of 100 to30,000, 300 to 10,000, 500 to 5,000, or 750 to 2,500 cps. Additionallyor alternatively, the hot melt adhesives can have a loop tack of 0.1,0.5, 1, or 1.5 and/or not more than 20, 15, 10, or 5 lbf as measuredaccording to ASTM D6195. Moreover, the hot melt adhesives can have aloop tack in the range of 0.1 to 20, 0.5 to 15, 1 to 10, or 1.5 to 5 lbfas measured according to ASTM D6195.

Furthermore, in various embodiments, the hot melt adhesives can have apeel strength of at least 1, 2, 5, 10, or 15 and/or not more than 50,40, 35, 30, or 25 g/mm as measured according to ASTM D903. Moreover, thehot melt adhesives can have a peel strength in the range of 1 to 50, 2to 40, 5 to 35, 10 to 30, or 15 to 25 g/mm as measured according to ASTMD903. Additionally or alternatively, the hot melt adhesives can have a90° peel strength of at least 0.05, 0.1, 0.2, or 0.5 and/or not morethan 20, 10, 5, or 1 lbf/inch as measured according to ASTM D903.Moreover, the hot melt adhesives can have a 90° peel strength in therange of 0.05 to 20, 0.1 to 10, 0.2 to 5, or 0.5 to 1 lbf/inch asmeasured according to ASTM D903.

According to various embodiments, the adhesives containing the inventivecopolymers can have a broad operating window and may have an applicationwindow from 80 to 230° C. This broad operating window can bedemonstrated by the peel strengths of the adhesives at differenttemperatures. For instance, the add-on level can be from 0.5-30 gsm. Inone or more embodiments, the hot melt adhesives can have a peel strengthfor samples applied at lower temperature (such as 100 to 145° C.) of atleast 2, 5, 25, or 40 and/or not more than 250, 200, or 175 g/mm asmeasured according to ASTM D903. Moreover, the hot melt adhesives canhave a peel strength for samples applied at lower temperature (such as100 to 145° C.) in the range of 2 to 250, 25 to 200, or 40 to 175 g/mmas measured according to ASTM D903. Additionally or alternatively, thehot melt adhesives can have a peel strength at for samples applied athigher temperature (such as 145 to 180° C.) of at least 1, 5, 30, or 40and/or not more than 250, 200, or 150 g/mm as measured according to ASTMD903. Moreover, the hot melt adhesives can have a peel strength forsamples applied at higher temperature (such as 145 to 180° C.) in therange of 1 to 250, 30 to 200, or 40 to 150 g/mm as measured according toASTM D903.

According to one or more embodiments, the hot melt adhesives can have aprobe tack of at least 0.1, 0.2, or 0.3 and/or not more than 5, 3, 2, or1 kg as measured according to ASTM D9279. Moreover, the hot meltadhesives can have a probe tack in the range of 0.1 to 3, 0.2 to 2, or0.3 to 5 kg as measured according to ASTM D9279. Furthermore, in variousembodiments, the hot melt adhesives can have a holding power at 50° C.of at least 0.1, 0.5, or 1 and/or not more than 50,000, 10,000, 5,000,1,000, 500, 100, 50, 20, 10, 7, or 4 hours as measured according to ASTMD3654. Moreover, the hot melt adhesives can have a holding power at 50°C. in the range of 0.1 to 10, 0.5 to 7, or 1 to 4 hours as measuredaccording to ASTM D3654.

In other embodiments, the hot melt adhesives can exhibit a holding powerat 60° C. of at least 5, 15, 20, or 25 minutes and/or not more than 150minutes. Additionally or alternatively, the hot melt adhesives canexhibit a holding power at 50° C. of at least 400, 600, 800, or 1,000minutes. The holding power at 50° C. and 60° C. can be measured bystabilizing glued carton substrates overnight at room temperature, whichis normally about +/−20 to 23° C., and then hanging the substrates in ashear bank oven in the peel mode. A weight is then hung under the gluedsubstrate. The time at which the weight drops due to failure is recordedfor each specimen. A minimum of eight specimens are needed for thistest. Parameters for this test are listed below.

Criteria Unit Condition Specimen size mm 25 × 60 Application temperatureC. 180 +/− 2    Open time s 2 Set time s 2 Line speed m/min 15  Bondingpressure kgf 1.2 (0.08 kgf per cm²) Coat weight g/m 3 +/− 0.09 Hangweight g 500 

According to various embodiments, the hot melt adhesives can have a peeladhesion failure temperature (“PAFT”) of at least 2, 10, 25, or 45and/or not more than 200, 120, or 80° C. as measured according to ASTMD4498. Moreover, the hot melt adhesives can have a PAFT in the range of2, 10 to 200, 25 to 120, or 45 to 80° C. as measured according to ASTMD4498. Additionally or alternatively, the hot melt adhesives can have ashear adhesion failure temperature (“SAFT”) of at least 2, 5, 10, 25,50, 75, or 90 and/or not more than 200, 150, or 125° C. as measuredaccording to ASTM D4498. Moreover, the hot melt adhesives can have aSAFT in the range of 2 to 200, 50 to 150, or 75 to 125° C. as measuredaccording to ASTM D4498.

In various embodiments, the hot melt adhesives can exhibit an effectiveset time of at least 0.1, 0.5, or 1 second and/or not more than 5seconds. In other embodiments, the hot melt adhesives can exhibit anopen time of at least 1, 5, or 10 and/or not more than 40, 30, or 20seconds.

In various embodiments, the hot melt adhesives can exhibit a lowtemperature performance fiber tear (“LTFT”) at −15° C. of at least 65,70, 75, 80, or 85 percent. Additionally or alternatively, the hot meltadhesives can exhibit an LTFT at −25° C. of at least 40, 50, 60, 70, or80 percent. The LTFT test consists of manually tearing a glued cartonsubstrate by hand under the condition of −15° C. or −25° C. The gluedcarton substrates have to be stabilized under the condition of −15° C.or −25° C. for at least 10 hours before the tearing. If 90% fiber of thesubstrates breaks, the test is considered a pass, and therefore, the hotmelt adhesive is considered to perform well at −15° C. or −25° C. Aminimum of 10 specimens are tested for each test. The LTFT testparameters are listed below:

Criteria Unit Condition Specimen size mm 50 × 100 Applicationtemperature C. 180 +/− 2    Open time s 2 Set time s 2 Line speed m/min15  Bonding pressure kgf 4 (0.08 kgf per cm²) Coat weight g/m 3 +/− 0.09

In various embodiments, the adhesives containing the inventivecopolymers do not exhibit substantial changes in color when subjected tostorage conditions at elevated temperatures over extended periods oftime. Before any aging due to storage occurs, the adhesives can have aninitial Gardner color of less than 18, 15, 10, 8, 5, 4, 3, 2, or 1 asmeasured according to ASTM D1544. After being heat aged at 177° C. forat least 96 hours, the adhesives can exhibit a final Gardner color ofless than 18, 15, 10, 7, 5, 3, 2 or 1 as measured according to ASTMD1544. Thus, the adhesives can retain a desirable color even afterprolonged storage and exposure.

In another embodiment of the invention, the low molecular weightpropylene-ethylene copolymer can be utilized in adhesive compositions asdescribed previously in this disclosure. In particular, the lowmolecular weight copolymer can be utilized to produce hot melt adhesiveshaving a wide process window and a high peel strength for the laminatedmaterials, such as, but not limited to, hygiene products, includingdestructive bond for the substrates. The adhesive composition containingthe low molecular weight copolymer may be applied in the range of about0.5 gsm to about 5 gsm, and add-on rates suitable for generatinglaminates with desired bond strength. The peel strength generated usingthe formulations of this invention can range from about 20 g/25 mm (˜1g/mm) to about 400 g/25 mm (16 g/mm), and to bond strengths that yieldsubstrate failure. In other embodiments, the peel strength can rangefrom at least 20 g/25 mm, 30 g/25 mm, 40 g/25 mm, 50 g/25 mm, 60 g/25mm, 70 g/25 mm, 80 g/25 mm, 90 g/25 mm, or 100 g/25 mm and/or not morethan 400 g/25 mm, 375 g/25 mm, 350 g/25 mm, 300 g/25 mm, 275 g/25 mm,250 g/25 mm, 225 g/25 mm, or 200 g/25 mm. Moreover, the adhesiveformulation can have a peel strength in the range of 20 g/25 mm to 375g/25 mm, 25 g/25 mm to 350 g/25 mm, 30 g/25 mm to 325 g/25 mm, 40 g/25mm to 300 g/25 mm, 50 g/25 mm to 275 g/25 mm, 60 g/25 mm to 250 g/25 mm,70 g/25 mm to 225 g/25 mm, or 80 g/25 mm to 200 g/25 mm. In variousembodiments of the present invention, the adhesive formulation isutilized as a hot melt adhesive and comprises at least one inventivecopolymer and at least one tackifier resin. Optionally, the hot meltadhesive can further comprise a wax, oil, and/or antioxidant. In oneparticular embodiment, the hot melt adhesive comprises about 50 to about60% by weight of the inventive low molecular weight copolymer and about40 to about 45% by weight of tackifier resin.

This invention can be further illustrated by the following examples ofembodiments thereof, although it will be understood that these examplesare included merely for the purposes of illustration and are notintended to limit the scope of the invention unless otherwisespecifically indicated.

EXAMPLES Example 1

In this example, various propylene-ethylene copolymers were produced ina two-liter stirred reactor with an average residence time of about onehour. The reactor temperature was maintained at approximately 140° C.and a pressure of 900 psig. The propylene was fed into the reactor as aliquid, while the ethylene was fed into the reactor as a gas. Thepolymerization occurred in the presence of a Ziegler-Natta catalyst,which was a titanium chloride on a magnesium chloride support. Thisparticular catalyst is a heterogeneous-supported catalyst system formedfrom titanium compounds in combination with alkyl aluminum co-catalyst(“TEAL”). The catalyst system contained an Al/Ti mole ratio of 21. Anyunreacted monomer and other vapors were vented from the reactor upondischarge of the copolymer.

Samples 1-11 were produced using the aforementioned catalyst system andan external electron donor. As noted below, the electron donor waseither cyclohexylmethyldimethoxysilane (“C”) ordicyclopentyldimethoxysilane (“D”). Comparative sample 1 (C1) wasproduced using the above catalyst system in the absence of any electrondonors. The amount of added electron donor varied for each sample asindicated by Donor/Ti molar ratio.

The copolymers produced from this reaction are described in TABLE 1below, along with their various properties and the reaction conditionsused to produce them. It should be noted that needle penetration wasmeasured using a penetrometer in accordance with ASTM D5 as discussedpreviously without actually running the specimens in water; however, thespecimens were conditioned in water prior to running the test.

TABLE 1 Copolymer Sample 1A 1B 1C 1D 1E 1F 1G 1H 1I 1J 1K C1 Al/Ti mole21 21 21 21 21 21 21 21 21 21 21 21 ratio Silane C C D D D D D D D D D —Donor Donor/Ti, 0.5 1.2 1.0 2.0 2.0 2.0 2.5 2.5 3.0 2.0 2.0 — mole ratioHydrogen 40 20 15 25 25 40 40 25 50 80 80 — (psig) Reactor 140 140 140140 140 140 140 140 140 140 140 140 Temp, ° C. Reactor 900 900 900 900900 900 900 900 900 900 900 900 Press. (psig) Catalyst 714.3 1003.3920.4 887.8 817.1 728.4 803.1 842.9 780.8 824.3 841.7 — Activity (g/g)Visc. @ 1853 5863 9088 9838 21125 6850 10238 16575 5525 1122 1748 7013190° C., cP Softening 130.3 142.2 134.8 131.6 128.6 121.8 126.3 132.6119 117.7 129.1 120.7 Point (° C.) Needle 20 14 15 29 17 20 22 21 28 2620 82 Pen. (dmm) Wt. % 15.2 12.5 17.5 24.6 20.2 22.6 25.3 22.6 25.2 21.119.5 21.7 Ethylene Wt. % 84.8 87.5 82.5 75.4 79.8 77.4 74.7 77.4 74.878.9 80.5 78.3 Propylene Poly 537.5 780.0 709.6 712.9 656.1 584.9 657.7690.3 652.0 661.9 675.9 720.9 Yield (g)

As shown above in TABLE 1, the addition of the external donor generallyincreased hardness, which was indicated by a decrease in needlepenetration, along with increasing the softening point and viscosity ofthe copolymers. As depicted in TABLE 1, samples produced with theexternal donor had significantly lower needle penetration values thanthe comparative sample (C1). Furthermore, it was observed that thecomparative sample was very tacky, but still lacked the strength of thesamples represented by needle penetration values below 30 dmm.

Previous studies indicate that external donor levels greater than 1.25:1(donor:Ti molar ratio) start to adversely impact properties of thecopolymers. In contrast to these studies, it was observed in thisexample that polymer properties improved at external donor levels ofgreater than 1.25:1 (donor:Ti molar ratio). Since the addition ofexternal donors can increase viscosity and molecular weight, theaddition of hydrogen, or a higher level of hydrogen, can be required toact as a chain terminator during polymerization compared topolymerization of a similar composition with no external donor added.

FIGS. 1A and 1B depict the viscoelastic characteristics of Samples 1B,1E, and 1F from TABLE 1. Furthermore, FIGS. 1A and 1B also provide theviscoelastic characteristics of various commercially-availablecopolymers to serve as a comparison. These commercially-availablecopolymers include INFUSE™ 9817 (Dow), AFFINITY™ GA1900 (Dow), andEastoflex™ E1060 (Eastman). FIG. 1A depicts the elastic modulus (G′) ofthe copolymers, while FIG. 1B depicts the tan delta of the copolymers.

As shown in FIGS. 1A and 1B, Sample 1B showed a desirable elasticmodulus (G′) plateau from −15 to 100° C., representing the elasticcharacteristics over a wide application temperature range. This isimportant in hot melt pressure sensitive adhesives (“PSA”) applications,such as tapes and labels, because the G′ plateau (i.e., the flatness ofthe curve) typically represents the energy absorption and desorptioncharacteristics, as well as the strength of the adhesive over a measuredtemperature range. After the plateau, the copolymer can start to flow.Previously, the flat nature of G′ for olefinic copolymers was onlyachievable through specialized catalytic processes (metallocenecatalysis) and/or incorporation of alpha-olefins.

Example 2

In this example, various propylene-ethylene copolymers were producedusing the process and system described in Example 1; however, theexternal electron donor used in this example wascyclohexylmethyldimethoxysilane. Furthermore, the amounts of electrondonor added for each sample were varied as indicated by the donor/Timolar ratio. The copolymers produced during this process are describedin TABLE 2 below, along with their various properties and the reactionconditions used to produce them.

TABLE 2 Copolymer Sample 2A 2B 2C 2D 2E 2F 2G Al/Ti mole 21 21 21 21 2121 21 ratio Donor/Ti, 1.1 1.2 0.5 1.0 1.0 1.5 2.0 mole ratio TEAL/Donor,31.3 29.6 70.0 32.9 32.9 24.7 16.5 mole ratio Hydrogen 40 20 20 25 25 2525 (psig) Reactor 140 140 140 140 140 140 140 Temp, ° C. Reactor 900 900900 900 900 900 900 Press. (psig) Catalyst 843.9 1003.3 1006.8 1001.3957.2 962.9 904.1 Activity (g/g) Visc. @ 3600 6600 5175 4865 7263 55384715 190° C., cP Softening 140.3 138.4 145.3 126.6 135.9 133 129.6 Point(° C.) Needle Pen. 10 14 17 32 24 23 32 (dmm) Wt. % 10.0 10.0 10.0 15.013.0 15.0 15.0 Ethylene Flow Wt. % 11.7 11.9 11.3 19.3 17.2 18.2 19.3Ethylene Wt. % 88.3 88.1 88.7 80.7 82.8 81.8 80.7 Propylene Poly 648.7780.0 760.1 772.0 738.0 757.8 726.0 Yield (g)

As depicted in TABLE 2, the use of cyclohexylmethyldimethoxysilane asthe external donor was able to produce copolymers with a desirablecombination of needle penetration and softening point. However, thisbalance was largely affected by the donor/Ti molar ratio. As shown inSamples 2F and 2G in TABLE 2, when the donor/Ti molar ratio wasincreased from 1.5:1 to 2:1, there was a slight decrease in softeningpoint and a significant increase in needle penetration, which was notdesirable.

Example 3

In this example, various propylene-ethylene copolymers were producedusing the process and system described in Example 1. The externalelectron donor used in this example was dicyclopentyldimethoxysilane.Furthermore, the amounts of electron donor added for each sample wasvaried as indicated by the donor/Ti molar ratio. The copolymers producedduring this process are described in TABLE 3 below, along with theirvarious properties and the reaction conditions used to produce them

TABLE 3 Copolymer Sample C1 C2 3A 3B 3C 3D 3E 3F Al/Ti mole 21 21 21 2121 21 21 21 ratio Donor/Ti, 0.3 1.5 3.0 3.0 4.0 2.0 2.0 3.0 mole ratioTEAL/Donor, 71.0 15.8 7.0 7.0 5.2 10.4 10.4 7.0 mole ratio Hydrogen 2025 80 50 50 80 25 50 (psig) Reactor 140 140 140 140 140 140 140 140Temp, ° C. Reactor 900 900 900 900 900 900 900 900 Press. (psig)Catalyst 862.0 1037.1 723.2 793.4 612.8 880.6 808.8 630.1 Activity (g/g)Visc. @ 7613 4625 1055 3150 5963 1053 16425 6250 190° C., cP Softening140.2 143.2 114.1 109.9 97.4 128.2 136.4 119.9 Point (° C.) Needle Pen.22 27 37 40 63 21 23 21 (dmm) Wt. % 10.0 15.0 15.0 17.5 17.5 13.0 15.013.0 Ethylene Flow Wt. % 14.5 17.3 24 25.8 31.1 18.2 21.3 24.2 EthyleneWt. % 85.5 82.7 76 74.2 68.9 81.8 78.7 75.8 Propylene Poly 644.0 816.2603.9 662.5 531.3 707.1 649.5 526.1 Yield (g) Copolymer Sample 3G 3H 3I3J 3K 3L 3M Al/Ti mole 21 21 21 21 21 21 21 ratio Donor/Ti, 3.0 3.0 3.03.0 3.0 2.0 2.0 mole ratio TEAL/Donor, 7.0 7.0 7.0 7.0 7.0 10.4 10.4mole ratio Hydrogen 33 33 30 30 80 80 80 (psig) Reactor 140 140 140 140140 140 140 Temp, ° C. Reactor 900 900 900 900 900 900 900 Press. (psig)Catalyst 653.5 648.1 658.6 584.1 750.9 636.9 817.1 Activity (g/g) Visc.@ 86000 93100 19275 16875 2332 2308 1590 190° C., cP Softening 132.2135.6 123.6 118.7 117.6 122.7 128.8 Point (° C.) Needle Pen. 13 8 19 1820 15 12 (dmm) Wt. % 13.0 13.0 13.0 13.0 12.0 12.0 12.0 Ethylene FlowWt. % 20.2 20.1 22.4 24.1 19.9 22.8 18.5 Ethylene Wt. % 79.8 79.9 77.675.9 80.1 77.2 81.5 Propylene Poly 545.7 541.2 549.9 487.7 627.0 511.4656.1 Yield (g)

As shown in TABLE 3, the amount of dicyclopentyldimethoxysilane neededto produce copolymers with the desired softening point and needlepenetration varies from the amount of cyclohexylmethyldimethoxysilaneneeded as shown above in Example 2. As demonstrated by comparativesamples C1 and C2, dicyclopentyldimethoxysilane levels generally neededto be at 2:1 or greater to achieve the desired properties in theproduced copolymers. Moreover, it was observed that copolymers producedusing dicyclopentyldimethoxysilane generally had much lower softeningpoints compared to those produced using cyclohexylmethyldimethoxysilane.Furthermore, the copolymers produced using dicyclopentyldimethoxysilanewere able to maintain desirable needle penetration values.

Comparing Samples 3C and 3F in TABLE 3 shows that increasing thedicyclopentyldimethoxysilane levels from 3:1 to 4:1 (at 17.5% ethyleneflow) results in more ethylene being incorporated into the polymer,thereby yielding a copolymer with a lower softening point.

Another noteworthy result is observed when comparing Samples 3D and 3F,both of which were produced using the same ethylene flow (13%) and hadthe same needle penetration (21 dmm). However, by increasing thedicyclopentyldimethoxysilane levels from 2:1 to 3:1, Sample 3Funexpectedly had an increased ethylene content (24.2%) compared toSample 3D (18.2%). This increased amount of ethylene led to the lowersoftening point in Sample 3F. Furthermore, it is theorized that thepropylene portion of Sample 3F is also more stereoregular (i.e., harder)than that of Sample 3D, thereby offsetting the softness that is usuallyaccompanied with a higher ethylene content.

Example 4

Adhesives were produced with Samples 1B, 1E, and 1F from Example 1. Theadhesives were produced in pint-sized cans using mechanical agitationwith a paddle-type agitator controlled by a variable speed motor with aheat block set at 177° C. The copolymer, along with antioxidant, wereintroduced into the pint-sized can and heated to 177° C. under anitrogen blanket. Resin and oil were then introduced into the mixtureafter the copolymer was melted. In some cases, wax can be also addedalong with resin and/or oil or in place of resin and/or oil. Thismixture was agitated for 30 minutes until it was completely homogenous.After thorough mixing, the adhesive was poured into a silicone-linedcardboard box and allowed to cool. TABLE 4, below, describes thecomposition and properties of these adhesives. In addition, comparativeadhesives were produced using INFUSE™ 9807 block copolymer (Dow) andKraton® D1102 copolymer (Kraton). It should be noted that thecompositional components recited in TABLE 4 are based on weightpercentage.

TABLE 4 Comparative Comparative Inventive Inventive Inventive MaterialsAdhesive 1 Adhesive 2 Adhesive 1 Adhesive 2 Adhesive 3 INFUSE ™ 20 9807Kraton ® 19.7 D1102 Copolymer 40 Sample 1B Copolymer 40 Sample 1ECopolymer 40 Sample 1F Regalite ™ 59.7 S5100 Regalite ™ 54 48.5 48.548.5 R1090 Kaydol 10.5 10.5 10.5 Mineral Oil Calsol 5550 25 19.6 OilIrganox ® 1 1 1 1 1 1010 Total 100 100 100 100 100 300 mm peel 13.1 14.62.3 21.5 13.3 strength (g/mm) Brookfield ~1800 ~1400 806 2167 940 Visc.177° C. (cps)

Viscoelastic characteristics of Comparative Adhesive 1, ComparativeAdhesive 2, Inventive Adhesive 2, and Inventive Adhesive 3 in TABLE 4were analyzed using Dynamic Mechanical Analysis (“DMA”). FIG. 2 depictsthe viscoelastic characteristics of these adhesives. The adhesives inTABLE 4 were also tested as disposable diaper construction adhesives andwere evaluated for adhesive peel strength as measured according to ASTMD903 using Instron after the adhesive had been applied between anonwoven fabric and polyethylene backing using air-assisted spiralspraying equipment (Acumeter Spray Coater).

Based on FIG. 2 and TABLE 4, the inventive adhesives show similarviscoelastic characteristics to adhesives produced fromcommercially-available copolymers. Furthermore, the inventive adhesivesalso exhibited superior strength as indicated by the higher peelstrengths.

Example 5

A pressure sensitive adhesive for labels was produced using the processdescribed in Example 4. The adhesive was produced using Sample 1E fromExample 1. TABLE 5, below, depicts the compositional makeup of thisadhesive.

TABLE 5 Inventive Adhesive Weight % Copolymer Sample 1E 60 Eastotac ™H100W 29.5 Calsol 5550 9.5 Antioxidant 1

The viscoelastic characteristics of this adhesive were measured usingDMA and are depicted in FIG. 3. This adhesive was also evaluated foradhesive peel (90° peel) strength and loop tack using Instron after theadhesive had been directly coated onto vellum using a hot melt knifecoater. The adhesive had a 90° peel strength of 0.6 lbf/inch and a looptack of 1.8 lbf.

Thus, this adhesive can be used as a label adhesive since it exhibitsdesirable viscoelastic characteristics as shown in FIG. 3 and idealadhesive peel and tack properties.

Example 6

Hot melt adhesives for packaging applications were produced using theprocess described in Example 4. All of the adhesives produced for thisexample comprised 39.8 weight percent of the respectivepropylene-ethylene copolymer, 39.8 weight percent of Eastotac™ H-100Whydrocarbon resin, 19.9 weight percent of Sasol H1 wax (Sasol), and 0.6weight percent of antioxidant. It should be noted that some of theseadhesives were formed from copolymers produced and described in theprevious examples (Samples 1F and 2B), which are noted in TABLE 6 below.As for the remaining listed copolymers (Samples 6A-6D), they wereproduced in accordance with the process described in Example 1. TABLE 6,below, provides various properties and characteristics of the producedadhesives. Furthermore, TABLE 6 notes the electron donor used to producethe listed copolymers. These electron donors includedcyclohexylmethyldimethoxysilane (“C”), dicyclopentyldimethoxysilane(“D”), and tetraethoxysilane (“TEOS”). The adhesives were evaluated forvarious adhesive properties, such as peel adhesion failure temperature(“PAFT”) (ASTM D4498), shear adhesion failure temperature (“SAFT”) (ASTMD4498), % fiber tear (ASTM D4498), and open time/set time (ASTM D4497).

TABLE 6 Copolymers in Adhesives Sample 1F Sample 2B Sample 6A Sample 6BSample 6C Sample 6D Properties of Needle Pen. 20 14 24 24 50 5Copolymers (dmm) Softening 121.8 138.4 126.5 135.9 145.6 154.7 Point (°C.) Electron D C D C TEOS C Donor Wt. % 22.6% 11.9% 21.7% 17.2% 13.3%10% Ethylene Properties of % Fiber Tear 75 75 25 100 25 0 the Adhesives(135° F.) % Fiber Tear 100 0 50 100 100 0 (Room Temp) % Fiber Tear 0 0 050 50 0 (40° F.) % Fiber Tear 0 0 0 50 75 0 (20° F.) Open Time/ >30/20 30/10 >30/20  30/10 20/10 32/20 Set Time (sec) SAFT/PAFT 98/56 115/68 99/51 99/75 99.6/74.6 100/62  (° C.) Brookfield 6850 6600 6700 7263 88506313 Visc. 177° C. (cps)

It should be noted that the adhesive produced with Sample 6D did nothave any noticeable fiber tear due to its low needle penetration asdepicted in TABLE 6.

The viscoelastic characteristics of the adhesive produced from Sample 1F(labeled as “Inventive Adhesive 5”) are compared in FIG. 4 with anadhesive produced from Affinity™ GA1950 (Dow). This comparative adhesivewas produced based on the same formulation used to produce the adhesivesin TABLE 6. This comparative adhesive is listed in FIG. 6 as“Comparative Adhesive 3.” It should also be noted that this comparativeadhesive had a SAFT of 93.6/3.6° C., a PAFT of 71.8/3.4° C., an opentime/set time of 15/5 seconds, and a Brookfield viscosity at 177° C. of177 cps. As shown in FIG. 4 and TABLE 6, the inventive adhesivesexhibited desirable viscoelastic characteristics and adhesive propertiesthat are comparable to standard adhesives in the industry.

Example 7

Hot melt adhesives for nonwovens were produced using the inventivepropylene-ethylene copolymers and various polymers. Thepropylene-ethylene copolymers used to manufacture these adhesive sampleswere produced in accordance with the process described in Example 1. Thevarious properties and characteristics of the copolymers used to producethe adhesive samples are listed in TABLE 7 below. Furthermore, TABLE 7indicates the electron donor that was used to produce the respectivecopolymer (cyclohexylmethyldimethoxysilane (“C”) ordicyclopentyldimethoxysilane (“D”)).

TABLE 7 Copolymer Sample 7A 7B 7C 7D Visc. @ 190° C., cP 2520 2960 25907363 Softening Point (° C.) 137.5 139.4 134.1 116.1 Needle Pen. (dmm) 1415 14 27 Wt. % Ethylene 11.7 11.9 11.3 19.3 Wt. % Propylene 88.3 88.188.7 80.7 Electron Donor D C C D

The adhesives were produced in accordance with the process described inExample 4. The adhesives were produced with various polymers andadditives including Vistamaxx™ 6202 (ExxonMobil), Infuse™ 9807 (Dow),L-MODU S400 (Idemitsu), Kraton® 1102 (Kraton), Kraton® 1161 (Kraton),Kraton® 1657 (Kraton), Regalite™ R1090 (Eastman Chemical), Kaydolmineral oil (Sonneborn), and Irganox® 1010 (BASF). The Brookfieldviscosity and the peel strength of the produced adhesives were measuredas described above. TABLE 8, below, describes the composition andproperties of these inventive adhesives, which are labeled as “IA.” Itshould be noted that the compositional components recited in TABLE 8 arebased on weight percentage and that all components add up to 100percent; however, this does not include the 1 percent of antioxidant(Irganox® 1010), which was added after all other components werecombined. The weight percentage for the antioxidant was based off thecombined weight percentage of the other components.

TABLE 8 Adhesives IA1 IA2 IA3 IA4 IA5 IA6 IA7 IA8 IA9 Composition Sample7A 70 of Adhesives Sample 7B 70 Sample 7C 70 Sample 7D 20 20 20 20 20 20Vistamaxx ™ 20 6202 Infuse ™ 20 9807 LMODU S400 20 Kraton ® 1102 20(SBS) Kraton ® 1161 20 (SIS) Kraton 1657 20 (SEBS) Regalite ™ 30 30 3048.5 48.5 48.5 48.5 48.5 48.5 R1090 Kaydol 10.5 10.5 10.5 10.5 10.5 10.5Mineral Oil Irganox ® 1 1 1 1 1 1 1 1 1 1010 Brookfield 1675 1775 143014900 7725 1250 3760 7200 10250 Visc. 177° C. (cps) Peel strength 9.86.6 4 21.5 18.6 9.8 6.6 4 21.5 (g/mm)

As shown in TABLE 8, the inventive adhesives exhibited desirableadhesive properties that are comparable to standard adhesives in theindustry.

Example 8

Hot melt adhesives for hygienic applications were produced using theinventive propylene-ethylene copolymers depicted in TABLE 9. Thecopolymers were produced in accordance with the process described inExample 1 using dicyclopentyldimethoxysilane as the electron donor.

TABLE 9 Copolymer Sample 8A 8B 8C Visc. @ 190° C., cP 20000 16000 2200Softening Point (° C.) 135 125 133 Needle Pen. (dmm) 22 17 20 Wt. %Ethylene 22 22 22 Wt. % Propylene 78 78 78

The adhesives were produced in accordance with the process described inExample 4. The adhesives were produced with various additives includingEastotac™ H-100W (Eastman Chemical), Regalite™ R1090 (Eastman Chemical),Kaydol mineral oil (Sonneborn), and Irganox® 1010 (BASF). TABLE 10,below, describes the composition and properties of these inventiveadhesives, which are labeled as “IA.” It should be noted that thecompositional components recited in TABLE 10 are based on weightpercentage.

The coatability, sprayability, and adhesive performance of the inventiveadhesives were compared against adhesives containing acommercially-available styrenic block copolymer (“SBC”) and acommercially-available olefin-based copolymer as shown in TABLE 10. Thecoating/spraying analysis was performed using an Acumeter and Nordson CFnozzle with different add-ons (2, 3, and 4 gsm) at 800, 600, and 400ft/min (6 gsm at 350 ft/min for 3 samples) at two different temperatures(137° C. and 163° C.). The tested substrates were 1 mil polyethylene anda 15 gsm spun bound nonwoven. The sprayability was observed and markedas “good,” “poor,” or “no” (i.e., not sprayable) after observing thespraying of adhesive at the designated temperature. The Brookfieldviscosity, softening point, needle penetration, and the peel strength ofthe produced adhesives were also measured as described above. The widthof the adhesive samples tested for peel strength was 15 to 20 mm.

TABLE 10 Adhesives Com. Com. SBC- Olefin- IA1 IA2 IA3 IA4 IA5 IA6 IA7Based Based Sample 8A 40 40 40 60 Sample 8B 40 60 Sample 8C 70Eastotac ™ 48.5 H-100W Regalite ™ 48.5 48.8 34.5 48.5 34.5 29 R1090Mineral Oil 10.5 10.5 10.5 4.5 10.5 4.5 Irganox ® 1 1 1 1 1 1 1 1010Brookfield 1688 2133 2760 6425 1515 5300 913 N/A N/A Visc. 190° C. (cps)Peel N/A 172 143 136 111 84 49 N/A N/A strength for 137° C. Samples (g)Peel 130 136 122 116 117.7 60 50 101 137 strength for 163° C. Samples(g) Sprayability Good/ Good/ Good/ Good/ Good/ Good/ Good/ Poor/ No/ at137° C./ Good Good Good Good Good Good Good Good Poor 163° C. Softening120.4 113.3 115.9 125.2 106.7 114.8 123.7 N/A N/A Point (° C.) Needle 5551 43 32 38 26 28 N/A N/A Penetration (dmm)

It should be noted that peel strength tests of 137° C. samples wereinconclusive for the two comparative commercial adhesives due to thepoor sprayability of these adhesives. As shown in TABLE 10, theinventive adhesives exhibited desirable coatability and sprayability atlow and high temperatures, thereby indicating a broad operating window.Furthermore, the inventive adhesives exhibited adhesive properties thatare either comparable or superior to standard adhesives in the industry.

Example 9

Hot melt adhesives for packaging applications were produced using theinventive propylene-ethylene copolymers depicted in TABLE 11.Furthermore, comparative adhesives were produced from a comparativepropylene homopolymer (“CPH”) as depicted in TABLE 11. The copolymersused to manufacture these adhesive samples were produced in accordancewith the process described in Example 1. Furthermore, TABLE 11 alsoindicates the electron donor that was used to produce the copolymers(cyclohexylmethyldimethoxysilane (“C”) or dicyclopentyldimethoxysilane(“D”)).

TABLE 11 Copolymer Sample CPH 9A 9B Visc. @ 190° C., cP 1028 3165 2520Softening Point (° C.) 135 132.1 137.5 Needle Pen. (dmm) 22 12 14 Wt. %Ethylene 0 9.9 16.7 Wt. % Propylene 100 90.1 83.3 Electron Donor C C D

The adhesives were produced in accordance with the process described inExample 4. The adhesives were produced with various additives includingEastotac™ H-100W (Eastman Chemical), Eastotac™ H-130W (EastmanChemical), Sasol wax H-1 (Sasol), and Irganox® 1010 (BASF). TABLE 12,below, describes the composition and properties of the inventiveadhesives, which are labeled as “IA,” and the comparative adhesives(“CA”). It should be noted that the compositional components recited inTABLE 12 are based on weight percentage. The initial viscosities of theadhesives were measured at 162° C. and 177° C., along with the SAFT,PAFT, and open/set times. The SAFT measurements were performed tounderstand the shear strength of the adhesives over a temperature periodin a SAFT oven. Viscosity profiles of the adhesives were generated todetermine the processability characteristics. Furthermore, the initialGardner color before aging and adhesive clarity at 177° C. were alsomeasured and observed.

TABLE 12 Adhesives CA1 CA2 IA1 IA2 IA3 CPH 39.8 59.8 Sample 9A 39.8 59.8Sample 9B 39.8 Eastotac ™ 39.8 H-100W Eastotac ™ 39.8 19.8 39.8 19.8H-130W Sasol wax H-1 19.8 19.8 19.8 19.8 19.8 Irganox ® 1010 0.6 0.6 0.60.6 0.6 Brookfield Visc. 465 750 3250 9062 575 162° C. (cps) BrookfieldVisc. 330 545 2192 6366 417 177° C. (cps) Open/Set time (s) 20/10 N/A15/10 15/10 N/A PAFT (° C.)   77.4 (4.7)  43.3 (3.8)  83.6 (2.6) 54.9(9)  63 (2) SAFT (° C.) 108.6 (5) 199.6 (2.5) 120.3 (0.4)  136.5 (0.4)101 (2) Gardner Color 2 4 5 6 1 (Initial) Adhesive Clarity clear clearhazy hazy clear (177° C.)

As shown in TABLE 12, the inventive adhesives exhibited adhesiveproperties that are either comparable or superior to adhesives producedfrom propylene. The inventive adhesives can exhibit desirable clarityand color, along with desirable processability as indicated by theirviscosities.

Example 10

Hot melt adhesives for packaging applications were produced using theinventive propylene-ethylene copolymers depicted in TABLE 13.Furthermore, comparative adhesives were produced from Affinity™ GA1950(Dow) and comparative polymers (“CP”) as depicted in TABLE 13. Thecopolymers used to manufacture these adhesive samples were produced inaccordance with the process described in Example 1. Furthermore, TABLE13 also indicates the electron donor that was used to produce thecopolymers.

TABLE 13 Copolymer Sample CP1 CP2 CP3 10A 10B Visc. @ 190° C., cP 83508812 29950 7825 19975 Softening Point (° C.) 157.5 155.8 157.3 111.9107.7 Needle Pen. (dmm) 7 9 1 29 37 Wt. % Ethylene 0 0 6.2 22.8 27.9 Wt.% Propylene 100 100 93.8 97.2 92.1 Electron Donor None None Anisole D D

The adhesives were produced in accordance with the process described inExample 4. The adhesives were produced with various additives includingRegalite™ R1090 (Eastman Chemical), Escorez® 5300 (Exxonmobil),Piccotac™ 1095 (Eastman Chemical), Piccotac™ 7590 (Eastman Chemical),Sasol wax H-1 (Sasol), and Irganox® 1010 (BASF). TABLE 14, below,describes the composition and properties of the inventive adhesives,which are labeled as “IA,” and the comparative adhesives labeled as“CA.” It should be noted that the compositional components recited inTABLE 14 are based on weight percentage and that all components add upto 100 percent; however, this does not include the 1 percent ofantioxidant (Irganox® 1010), which was added after all other componentswere combined. The weight percentage for the antioxidant was based offthe combined weight percentage of the other components.

The initial viscosities of the adhesives were measured at 150° C., 162°C., and 177° C., along with the SAFT, PAFT, and open/set times.Viscosity profiles of the adhesives were generated to determine theprocessability characteristics of the adhesives. The SAFT measurementsare performed to understand the shear strength of the adhesives over atemperature period in a SAFT oven. Furthermore, the adhesive clarity at177° C. was also observed.

TABLE 14 Adhesives CA1 CA2 CA3 CA4 IA1 IA2 CA5 CA6 IA3 CompositionAffinity 40 of Adhesives GA1950 CP1 40 CP2 40 40 CP3 40 40 10A 40 40 10B40 Regalite ™ 40 40 40 40 40 40 R1090 Escorez ® 40 40 40 5300 Piccotac ™1095 Piccotac ™ 7590 Sasol wax 20 20 20 20 20 20 20 20 20 Irganox ® 1 11 1 1 1 1 1 1 1010 Visc. 150° C. 1867 7308 3685 30150 675 3360 N/A N/A4000 (cps) Visc. 162° C. 1300 810 940 3275 417 2490 1150 3080 2935 (cps)Visc. 177° C. 932 607 670 1887 310 1320 860 2370 1872 (cps) Open/Set30/40 40/10 — — — — — — — time (s) PAFT (° C.) 60.6 72.9 75 75.1 67.3 5071.5 73.4 62.5 SAFT (° C.) 97.8 109.1 110 125.2 91.9 88.8 107.4 125.5 96Clarity Clear Clear Clear Clear Clear Clear Clear Clear Clear (177° C.)Adhesives CA7 CA8 IA4 IA5 CA9 CA10 IA6 IA7 Composition Affinity ofAdhesives GA1950 CP1 CP2 40 40 CP3 40 40 10A 40 40 10B 40 40 Regalite ™R1090 Escorez ® 5300 Piccotac ™ 40 40 40 40 1095 Piccotac ™ 40 40 40 407590 Sasol wax 20 20 20 20 20 20 20 20 Irganox ® 1 1 1 1 1 1 1 1 1010Visc. 150° C. N/A 248300 3029 607 26550 87000 3604 752 (cps) Visc. 162°C. 910 2895 1980 432 890 2820 2390 570 (cps) Visc. 177° C. 685 2050 1692317 815 1900 1507 427 (cps) Open/Set — — — — — — — — time (s) PAFT (°C.) 76 76.2 71.2 49.4 79.3 79.3 70.6 47.7 SAFT (° C.) 109.6 121.8 95.788.1 108.2 120.1 92 99.4 Clarity Clear Clear Clear Clear Clear ClearClear Clear (177° C.)

As shown in TABLE 14, the inventive adhesives exhibited adhesiveproperties that are either comparable or superior to common adhesives inthe industry. The inventive adhesives can exhibit desirable clarity anddesirable processability as indicated by their viscosities. Furthermore,as shown in TABLE 14, the inventive adhesives can exhibit superioradhesive properties.

Example 11

Hot melt pressure-sensitive adhesives for tapes and labels were producedusing an inventive propylene-ethylene copolymer (Sample 7D from Example7). The adhesives were produced in accordance with the process describedin Example 4. The adhesives were produced with VistamaxxlM 6202(Exxonmobil), Kraton® 1162 (Kraton), Kraton® 1657 (Kraton), Regalite™R1090 (Eastman Chemical), Kaydol mineral oil (Sonneborn), and Irganox®1010 (BASF). TABLE 15, below, describes the composition and propertiesof the inventive adhesives. It should be noted that the compositionalcomponents recited in TABLE 15 are based on weight percentage. The probetack (kg) of the adhesive was measured according to ASTM D9279 and thehold power (hours) was measured according to ASTM D3654.

TABLE 15 Adhesives IA1 IA2 IA3 Composition Sample 7D 20 20 20 ofAdhesives Vistamax ® 20 6202 Kraton ® 1161 20 Kraton ® 1657 20Regalite ™ 48.5 48.5 48.5 R1090 Mineral Oil 10.5 10.5 10.5 Irganox ®1010 1 1 1 Brookfield 14900 7200 10250 Visc. 177° C. (cps) Probe Tack0.5 0.4 0.4 (kg) Hold Power 3.5 .01 1.6 (on SS) (hours)

As shown in TABLE 15, the inventive adhesives exhibited adhesiveproperties that are either comparable or superior to common adhesives inthe industry.

Example 12

Polymer blends were produced to observe the effects that certainpolymers had on particular blends. In this example, a commercialpropylene homopolymer (Exxon™ PP3155) was compared to a propylenehomopolymer prepared in accordance with Example 1. This propylenehomopolymer (“Sample 12A”) was produced without an electron donor andhad a softening point of 157.5° C. and a needle penetration of 7 dmm.These two homopolymers were separately combined with Kraton® G1650(Kraton), Kraton® G1651 (Kraton), CaCO₃, Drakeol® 34 oil (CalumetSpecialty Products), and Kristalex™ 5140 (Eastman Chemical) to producepolymer blends. The composition and properties of these polymer blendsare depicted in TABLE 16 below. It should be noted that all compositionvalues in TABLE 16 are based on weight percentages.

Furthermore, various properties of the polymer blends were measured asshown TABLE 16. The tested properties included Shore A hardness (ASTMD2240), melt flow rate (ASTM D1238), tear strength (ASTM D624), 100%modulus (ASTM D412), 200% modulus (ASTM D412), 300% modulus (ASTM D412),elongation at break (ASTM D412), tensile strength (ASTM D412), andYoung's Modulus (ASTM E111-04).

TABLE 16 Blends Non-Commercial Commercial Composition Exxon ® 3155 (PP)15 of Blends Sample 12A 15 Kraton ® G1650 17.5 17.5 Kraton ® G1651 17.517.5 CaCO₃ 15 15 Drakeol ® 34 oil 25 25 Kristalex ™ 5140 10 10 Hardness(Shore A) 45 70 Melt Flow Rate 31.74 18.1 (22° C./5.16 kg) Tear Strength170 281 (lbf/in) 100% Modulus 209 466 200% Modulus 298 670 300% Modulus415 932 Elongation at Break 425 677 Tensile Strength 576 2785 Young'sModulus 0.324 0.67

As shown above, the non-commercial homopolymer produced using theprocess described above can improve polymer blends in a similar manneras commercial homopolymers.

The inventors hereby state their intent to rely on the Doctrine ofEquivalents to determine and assess the reasonably fair scope of thepresent invention as it pertains to any apparatus not materiallydeparting from but outside the literal scope of the invention as setforth in the following claims.

The preferred forms of the invention described above are to be used asillustration only, and should not be used in a limiting sense tointerpret the scope of the present invention. Modifications to theexemplary embodiments, set forth above, could be readily made by thoseskilled in the art without departing from the spirit of the presentinvention.

Example 13

Hot melt adhesives for hygiene and packaging applications were producedusing the inventive propylene-ethylene copolymers depicted in TABLE 17.The copolymers used to manufacture these adhesive samples were producedin accordance with the process described in Example 1. Furthermore,TABLE 17 also indicates the electron donor that was used to produce thecopolymers.

TABLE 17 Copolymer Sample 13A 13B 13C 13D 13E 13F Visc. @ 1813 206316525 18400 19000 1840 190° C., cP Softening 133.5 130.6 110.4 115.9117.4 132.7 Point (° C.) Needle Pen. 22.8 22.7 32.8 28.1 23.6 22.8 (dmm)Wt. % 16 16 22 21 20 16 Ethylene Wt. % 84 84 78 79 80 84 PropyleneElectron Donor D D D D D D

The adhesives were produced in accordance with the process described inExample 4. The adhesives were produced with various additives includingRegalite™ R1090 (Eastman Chemical), Eastotac™ H100W (Eastman Chemical),Kaydole® mineral oil (Sonneborn), Licocene® wax (Clarient), Sasol waxH-1 (Sasol), and Irganox® 1010 (BASF). TABLE 18 and TABLE 19, below,describes the composition and properties of the inventive adhesives.TABLE 18 contains inventive adhesives that can be utilized for thehygiene construction market, while TABLE 19 contains inventive adhesivesthat can be used for packaging. It should be noted that thecompositional components recited in TABLE 18 and TABLE 19 are based onweight percentage and that all components add up to 100 percent.

TABLE 18 Adhesives IA1 IA2 IA3 IA4 IA5 IA6 IA7 IA8 IA9 CA1 CA2 CA3 CA413C 40 — — 35 — — 35 — — 13D — 40 — — 35 — — 35 — 13E — — 40 — — 35 — —35 Regalite ® 48.5 48.5 48.5 46.5 46.5 46.5 46.5 46.5 46.5 R1090Kaydol ® 10.5 10.5 10.5 10.5 10.5 10.5 10.5 10.5 10.5 Oil Sasol ® — — —7 7 7 — — — H1 wax Licocene ® — — — — — — 7 7 7 6102 Irganox ® 1 1 1 1 11 1 1 1 1010 300 mm Peel Strength - 24 Hrs at Room Temperature(Signature Nozzle Sprayed Samples) g/mm 2.64 3.17 2.63 4.62 4.51 5.14.64 4.03 4.86 1.73 4.64 4.62 3.44 Std. Dev. 0.2 0.43 0.19 0.2 0.42 0.280.33 0.29 0.36 0.17 0.19 0.37 0.23 300 mm Peel Strength - BodyTemperature (Signature Nozzle Sprayed Samples) g/mm 2.83 3.34 3.27 5.084.81 5.58 4.45 4.52 4.55 1.91 4.99 4.39 3.43 Std. Dev. 0.29 0.22 0.090.19 0.49 0.52 0.13 0.39 0.52 0.12 0.2 0.17 0.05 300 mm Peel Strength -2 Weeks Aged (Signature Nozzle Sprayed Samples) g/mm 2.75 3.21 2.91 4.745.23 6.82 4.91 5.05 6.13 2.71 5.11 4.16 3.39 Std. Dev. 0.15 0.38 0.220.26 0.55 0.59 0.27 0.69 0.51 0.34 0.16 0.21 0.34 Spray 305 to 350 305350 325 335 Temperature (° F.) Brookfield Viscosity and Gardner ColorInitial 1600 1470 1657 925 660 992 1017 1145 1102 1780 3287 2250 1617Viscosity at 177° C. (cPS) 96 hrs at 1390 1308 1507 857 2260 910 9901050 975 2245 987 240 177° C. Aged Viscosity (cPS) Initial 1 1 1 1 1 1 11 1 1 1 2 8 GardnerColor) 96 hrs at 8 8 6 7 8 7 6 7 7 9 12 18 18 177° C.Aged Gardner Color 300 mm Peel Strength - 24 Hrs at Room Temperature (CFNozzle Sprayed Samples) g/mm 5.58 5.99 6.24 8.36 8.33 10.28 9.49 9.069.94 Std. Dev. 0.36 0.39 0.68 0.24 0.71 0.51 0.43 0.93 0.61 300 mm PeelStrength - Body Temperature (CF Nozzle Sprayed Samples) g/mm 5.75 6.26.58 8.94 9.24 10.11 8.92 9.79 9.44 Std. Dev. 0.32 0.15 0.49 0.44 0.510.38 0.36 0.77 0.49 300 mm Peel Strength - 2 Wks Aged (CF Nozzle SprayedSamples) g/mm 5.88 6.76 6.26 10.31 10.39 14.32 12.06 11.69 11.49 Std.Dev. 0.25 0.36 0.35 0.85 1.44 0.75 0.88 0.61 0.42 Spray 270 to 350Temperature (° F.)

TABLE 18, above, describes the composition and properties of theinventive adhesives, which are labeled as IA1-IA9. Comparativecommercial adhesives were also analyzed and are labeled as CA1-CA4.CA1-CA3 utilize olefin based polymers for adhesives in hygieneconstruction. CA4 is also a commercial adhesive using styrenic blockcopolymers for use in hygiene construction. The hygiene adhesives inTABLE 18 made using the inventive polymers show broad operating windowsusing wide range of spraying/coating techniques (signature, summit, CF,omega, intermittent, -slot, etc.) with excellentsprayability/coatability characteristics over a wide range oftemperatures (270° F. to 350° F.) with good adhesive peel at roomtemperature, body temperature and under aged conditions (elevatedtemperature and room temperature) with an add-on level varying from0.5-8.0 gsm. Thermal stability, Garner color and Brookfield viscositystability of the adhesives made using inventive polymers are alsoexcellent, and the adhesives made using the inventive polymers are clearat room temperature with no color and no odor.

The initial viscosity of the adhesives in TABLE 19 was measured at 177°C., along with the SAFT, PAFT, % fiber tear and open/set times. Agedviscosities of the adhesives were generated to determine theprocessability characteristics and long term aging stability of theadhesives. The PAFT and SAFT measurements are performed to understandthe peel adhesion and shear strength of the adhesives over a temperatureperiod in a SAFT oven. Furthermore, the initial and aged color inGardner color scale was also measured.

TABLE 19 IA10 IA11 IA12 IA13 IA14 IA15 IA17 IA18 IA19 IA20 13A 60 75 6075 13F 60 75 60 75 60 75 Regalite ® R1090 14.5 4.5 14.5 4.5 14.5 4.514.5 4.5 Eastotac ® H100W 14.5 4.5 Licocene ® 6102 24.5 19.5 24.5 19.524.5 19.5 Sasol H1 Wax 24.5 19.5 24.5 19.5 Irganox ® 1010 1 1 1 1 1 1 11 1 1 Adhesive Properties Initial Brookfield viscosity 742.5 1170 8001165 790 2640 552 935 565 930 @ 177° C. Aged (96 hrs at 177° C.) 7151070 677 1035 715 2377 445 790 452 795 Brookfield viscosity @ 177° C.Initial Gardner color 1 1 1 1 1 1 1 1 1 1 Aged Gardner color (96 hrs 8 88 8 10 7 8 7 8 6 at 177° C.) PAFT, Kraft paper (° C.) 27.2 26.5 26.726.5 32.1 31 PAFT Std. Deviation 1.3 0.1 0.4 0.4 4.3 3.6 SAFT, Kraftpaper (° C.) 123.3 70 108.7 127.3 118.5 110.8 SAFT - Std. Deviation 3.58.5 12.9 3.3 2.3 1.9 Open/Set time (sec) 40/18 32/12 35/13 32/15 32/945/17 20/25 20/27 15/20 % Fiber Tear 0° C. 100 (3x) 100 (3x) 100 (3x)100 (3x) 100 (3x) 100 (3x) 0 (3x) 0 (3x) 0 (3x) 0 (3x) (3x = 3 samples)Room Temperature 100 (3x) 100 (3x) 0 (3x) 0 (3x) 0 (3x) 0 (3x) (3x = 3samples) 135° C.  0 (3x)  0 (3x)  0 (3x)  0 (3x)  25 (3x)  0 (3x) 0.5(3x)  0 (3x) 0 (3x) 0 (3x) (3x = 3 samples)

Example 14

For this Example, an adhesive containing the low molecular weightpropylene-ethylene copolymer was prepared. The adhesive comprised 60weight percent of the low molecular weight ethylene/propylene copolymerand 40 weight percent of Regalite® 1090 hydrocarbon resin (InventiveCopolymer 60/40).

21.91 kg (48.2 bs.) of adhesive composition was prepared in a conicalreactor equipped with intermeshing spiral agitators and a distillationcolumn. The composition of the adhesive composition was as follows:

-   -   (a) low molecular weight propylene-ethylene copolymer 12.71 kg        (27.99 lbs.) (˜59.5 weight percent);    -   (b) Regalite® 1090 resin 8.98 kg (19.75 lbs.) (˜39.5 weight        percent);    -   (c) Irganox® 1010 antioxidant 0.22 kg (0.4925 lbs.) (˜0.985        weight percent); and    -   (d) Eastobrite® Optical Brightener OB-1 0.0011 kg (0.0025 lbs.)        (0.005 weight percent).

Before starting the batch, the vacuum header in the column was adjusted,and the temperature of the system was subsequently set to 150° C. bycirculating hot oil in the jacket of the distillation column. Isopar™ Land dry ice were charged to the cold trap and the actions were recordedon the production batch sheet. The oil recirculation in the distillationcolumn was then shut off to maintain the temperature at 150° C. At thatpoint, the following ingredients were charged to the reactor under apurge of 10 ft³/hr nitrogen: (a) Regalite® 1090 resin; (b) Irganox® 1010antioxidant; and (c) Eastobrite® optical brightener OB-1 in the amountsnoted above.

The temperature of the heating oil was then raised to 190° C. ensuringthat the adhesive composition temperature reached a maximum temperatureof 180° C. When the adhesive composition temperature reached 130° C.,the agitator was started and operated at 6 minutes forward and 6 minutesreverse at 25 rpm. When the oil temperature reached 180° C., the lowmolecular weight copolymer (13.52 kg (29.75 lbs.) or 59.50% of totalformula) was added in two aliquots of 6.82 kg (15 lbs.) and 6.59 kg(14.75 lbs.), respectively, through the main port. After addition ofeach aliquot at 180° C., the mixture was stirred at 25 rpm, for 30minutes. When the last aliquot of the copolymer was added, the mixturewas stirred for 60 minutes at 180° C. and 25 rpm, and then the hot meltadhesive composition was extruded into wax-coated boxes through the ramvalve. The system was purged with 30 ft³/hr nitrogen and the reactor wasdrained for 30 minutes at 180° C. After the 30 minutes hold time fordraining, the adhesive composition temperature was decreased to 75° C.and the draining of the reactor was continued.

Example 15

For this example, an adhesive comprising around 52 weight percent of theinventive low molecular weight propylene-ethylene copolymer wasproduced.

113.56 kg (250.14 lbs.) of adhesive composition were prepared in aconical reactor equipped an intermeshing spiral agitators and adistillation column. The adhesive composition was as follows:

-   -   (a) Inventive Low Molecular Weight Copolymer—59.07 kg (130.12        lbs.) 52.0 weight percent;    -   (b) Regalite® 1090 resin—51.08 kg (112.5 lbs.) 45.0 weight        percent;    -   (c) Sasol® H1 Wax—2.27 kg (5.0 lbs.) 2.0 weight percent;    -   (d) Irganox® 1010 antioxidant—1.13 kg (2.49 lbs.) 0.995 weight        percent; and    -   (e) Eastobrite® optical brightner OB-1 0.0057 kg (0.0125 lbs.)        0.005 weight percent.

Before starting the batch, the vacuum header in the column was adjustedand the temperature of the system was subsequently set to 150° C. bycirculating hot oil in the jacket of the distillation column. Isopar™ Land dry ice were charged to the cold trap; the actions were recorded onthe production batch sheet. The oil recirculation in the distillationcolumn was then shut off to maintain the temperature at 150° C. At thatpoint, the ingredients listed below were charged to the reactor under apurge of 10 ft³/hr nitrogen.

Regalite ® 1090 resin 51.14 kg (112.5 lbs.) Sasol ® H1 Wax 2.27 kg (5.0lbs.) Irganox ® 1010 antioxidant 1.14 kg (2.49 lbs.) Eastobrite ® OB 10.0057 kg (0.0125 lbs.)

The temperature of the heating oil was then raised to 190° C., therebyensuring that the adhesive composition temperature reached a maximumtemperature of 180° C. When the blend temperature reached 130° C., theagitator was started and operated at 6 minutes forward and 6 minutesreverse at 25 rpm. When the oil temperature reached 180° C., the lowmolecular weight copolymer was then added (59.1 kg-130 lbs.- or 52.0% oftotal formula) in five aliquots (four of 13.64 kg (30 lbs.) each and thelast of 4.55 kg (10 lbs.)) through the main port. After each addition at180° C., the mixture was stirred at 25 rpm for 30 minutes. When the lastaliquot of low molecular weight copolymer was added, the mixture wasstirred for 60 minutes at 180° C. and 25 rpm, and then the hot meltadhesive was extruded into wax-coated boxes through the ram valve. Thesystem was purged with 30 SCFH nitrogen, and the reactor was drained for30 minutes at 180° C. After the 30 minutes hold time for draining, thecomposition temperature was decreased to 75° C. and the draining of thereactor was continued.

Example 16: Preparation of Hot Melt Adhesive Containing Aerafin® 180

27.27 kg (59.993 lbs.) of adhesive were prepared in a conical reactorequipped with a distillation column. Before starting the batch, thevacuum header in the column was adjusted and the temperature of thesystem was subsequently set to 150° C. by circulating hot oil in thejacket of the distillation column. Isopar™ L and dry ice were charged tothe cold trap; the actions were recorded on the production batch sheet.The oil recirculation in the distillation column was then shut off tomaintain the temperature at 150° C.

At that point, the ingredients listed below were charged to the reactorunder a purge of 10SCFH nitrogen.

-   -   (a) Regalite® 1090 resin—12.68 kg (27.9 lbs.) 46.50 weight        percent;    -   (b) Kaydol® Mineral Oil—2.86 kg (6.3 lbs.) 10.00 weight percent;    -   (c) Sasol® H1 Wax 1.91 kg (4.2 lbs.) 7.00 weight percent;    -   (d) Irganox 1010 antioxidant 0.27 kg (0.59 lbs.) 0.983 weight        percent; and    -   (e) Eastobrite® OB-1 0.0014 kg (0.003 lbs.) 0.005 weight        percent.

The temperature of the heating oil was then raised to 190° C., therebyensuring that the adhesive composition temperature reached a maximumtemperature of 180° C. When the adhesive composition temperature reached130° C., the agitator was started and operated at 6 minutes forward and6 minutes reverse at 25 rpm. When the oil temperature reached 180° C.,the Comparative Aerafin® 180 copolymer (9.55 kg-21 lbs., or 35% of totalformula) was then added in three aliquots of 7 lbs. through the mainport. After each addition at 180° C., the mixture was stirred at 25 rpmfor 30 minutes. When the last aliquot of copolymer was added, themixture was stirred at 180° C. and 25 rpm, and then the hot meltadhesive was extruded into wax-coated boxes through the ram valve. Thesystem was purged with 30 SCFH nitrogen and the reactor was drained for30 minutes at 180° C. After 30 minutes of hold time for draining, thepolymer temperature was decreased to 75° C. and the draining of thereactor was continued. The final composition of the adhesive was asfollows:

Comparative Aerafin ® 9.55 kg (21 lbs.) 180 35.017% Regalite ® 109012.68 kg (27.9 lbs.) resin 46.50% Kaydol ® Mineral 2.86 kg (6.3 lbs.)Oil 10.00% Sasol ® H1 Wax 1.91 kg (4.2 lbs.) 7.00% Irganox ® 1010 0.27kg (0.59 lbs.) antioxidant 0.983% Eastobrite ® optical 0.0014 kg (0.003lbs.) brightner OB 1 0.005%

The following test methods and sample preparation techniques wereutilized to test the produced adhesives and the copolymers utilized inExamples 14-16.

Thermal Properties Measurement

Thermal properties, such as melt temperature and energy were evaluatedusing a Mettler Toledo differential Scanning calorimeter, DSC2 STAR^(e)System (1900 Polaris Parkway, Columbus, Ohio, USA 43240), equipped witha 400 w furnace supply and a Ceramic FRS2 High DSC sensor. Theinstrument was controlled by a DSC STAR^(e) Software, Version 13.00a(build 6917), installed on a HP Z230 workstation. The software was alsoused for data processing.

10-15 mg of sample was placed in a 40 μl aluminum crucible (model 1/3 ME51119870, without pin) and then sealed with an aluminum lid (model 1/2ME51119871).

The sealed crucible was placed in a DSC furnace and heated from roomtemperature to 200° C., held at 200° C. for 10 minutes, and then cooledto −100° C., held at that temperature for 10 minutes, and heated againto 200° C. Finally, the sample was cooled from 200° C. to roomtemperature. The heating rate was 10 c/min and the cooling rate was −10°C./min. The thermograms for both heating and cooling phases wererecorded. The melt and crystallization, as well as the melting andcrystallization energies were evaluated from the data in the thermograms(second heat and first cool) using the DSC STAR^(e) Software.

Crystallinity by X-Ray Diffraction

The crystallinity of the polymers was evaluated using a PANalyticalEmpyrean XRD Spectrometer (2555 55th Street, Boulder, Colo., USA 80301)equipped with an anode energized to 45 kV and 40 mA to produce acollimated, monochromatic Copper-Kα radiation striking the sample andproducing diffraction patterns. The patterns were collected, in theBragg Brentano reflection geometry, with a detector angle fixed to 2times the incident angle (θ−2θ), from 5 degree 2θ angle to 90 degree 2θangle, for a sampling width of 0.02 degrees, and a step time of 160seconds.

The samples were cut into ˜1 inch squares that were 3 to 6 mm thick andthen mounted flat on a stationary xyz stage using double sided tape. Thesamples were exposed to the X-ray beam and the diffraction patterns werecollected.

Peak deconvolution of X-ray diffraction patterns were performed usingJADE XRD Pattern Processing, Identification and Quantification Software(Version 9.5.0) from Materials Data Incorporated (MDI, Livermore,Calif.). An estimation of percent crystallinity was calculated based onthe integrated intensities of de-convoluted and fitted diffraction peaksfrom 10 degrees 2θ to 32 degrees 2θ. From the integrated diffractionpeaks and the use of the Scherrer equation, estimations of crystallitesizes were then calculated. Fitted diffraction peaks with crystallitesizes greater than 30 Å was defined as belonging to crystalline regionsof the polymer and peaks with crystallite size less than or equal to 30Å were defined as belonging to amorphous regions of the polymer.

The inventive low molecular weight copolylmer had a crystallinity of25+/−2%, while the crystallinity of the comparative Aerafin® 180copolymer had crystallinity of 20+/−2 when measured by X-raydiffraction.

Rheology Temperature Sweep

The viscoelastic properties of the polymer were evaluated using TAInstruments 400801 series/ARES G1 controlled with a TA Orchestrator4800-0026 (Firmware ARES V7.2.0.4) installed on HP Compaq computer.Parallel plate geometry of either 8 or 25 mm was used. The gap betweenplates was 1 mm. When the 8 mm plates were used the followingexperimental setup was adopted: 5% maximum applied strain, 1,000 g-cmmaximum torque, 30 g-cm minimum torque, 300% strain adjustment ofcurrent strain, and 0.5% strain. In the case the 25 mm plates were usedthe conditions adopted were 50% maximum applied strain, 100 g-cm maximumtorque, 30 g-cm minimum torque, 30% strain adjustment of current strain,and 5% strain.

A temperature ramp of 6° C./min, a frequency of 10 rad/s, and atemperature range of −80° C. to 170° C. were adopted for all the runs.

The viscoelastic properties determined by using this method encompassstorage and loss moduli (G′ and G″) and tangent delta (tan δ). Also, thetechnique allows determination of the glass transition temperature (Tg)of the polymer.

FIGS. 5 and 6 show the difference between the profiles of theComparative Aerafin® 180 copolymer and the Inventive Low MolecularWeight Copolymer. More notably, the Inventive Low Molecular WeightCopolymer showed two transition temperatures, the first around −29.5° C.and the second transition at about 68.3° C., while the ComparativeAerafin® 180 copolymer showed only one transition at −31.5° C.

Also, the Inventive Low Molecular Weight Copolymer displayed a higherstrength, characterized by a lower tan delta value, than the ComparativeAerafin® 180 copolymer. This is also highlighted at 25° C. by thedisplay of a high value of the storage modulus G′.

Rheology—Capillary Rheometry—Viscoelastic Properties as a Function ofShear Rate

Ceast SR20 Instron Capillary Rheometer was used to measure the meltviscosity at the shear rate range of 10-30,000 1/sec. 0.5 mm. Die wasused to measure the melt viscosity, pressure, fluid volume and fluidvelocity, at 140° C., as a function of shear rate. 20-30 grams of sampleamount were needed for the measurement.

The inventive low molecular weight copolymer was relatively Newtonianover a wide range of shear rates as shown in FIG. 7. The low resistanceto flow for the molten inventive low molecular weight copolymer makes italso easier to process and use in applications where high shear istypically encountered.

Molecular Weight Determination

The samples were analyzed using a Malvern Viscotek HT-350A HighTemperature Gel Permeation Chromatograph equipped with 2 Viscotek VE1122pumps (main and an auxiliary); a Viscotek Model 430 vortex heaterstirrer autosampler; a VE7510 GPC degasser; a HTGPC Module 350A oven; aMicrolab 500 series auto syringe for sample preparation, and a tripledetection system consisting of a combination of laser light scattering,refractometer, and differential viscosity detectors. The GPC containedPLGel 5 micron Guard 50×7.5 mm column and 2×PLGel 5 micron Mixed-C300×7.5 mm columns running 1,2,4-trichlorobenzene as the solvent at aflow rate of 0.7 ml/min at 135° C. The instrument was controlled byMalvern OmniSEC software.

50 to 70 mg of each sample were weighed into sample vials and mixed with10 mL of 1,2,4-trichlorobenzene to make about 5.0 to 7.0 mg/mL blend.The vials were placed in a Viscotek Model 430 vortex heater stirrerautosampler to equilibrate at room temperature, for about 1 hour, underagitation using a magnetic stirrer bar, then the samples were heated forno more than 4 hours at 135° C.

Analysis of Results

For each specimen, two injections were used and the chromatograms foreach injection were collected. The samples were analyzed by conventionalGPC using a single narrow polystyrene standard calibration, lightscattering, triple detection and universal calibration. The analysis ofthe light scattering data, the conventional GPC analysis, tripledetection analysis, and universal calibration analysis were done usingsame Malvern OmniSEC software. The weight average molecular weight (Mw),number average molecular weight (Mn), and the Z-average molecular weight(Mz) were determined for each sample using the Malvern OmniSEC software.

The weight average molecular weight (Mw), number average molecularweight (Mn), Z-average molecular weight (Mz), polydispersibility index(Mw/Mn) were determined for each sample.

Effects of Molecular Weight Polydispersibility on Performance of HotMelt Adhesives

Mn, Mw, Mz and Mw/Mn for each sample is shown in Table 20 providedbelow. For statistical design of experiments purposes the molecularweights, expressed as Mw/Mn, were codified into design unit values (F:molecular weight) of −1, −0.5, 0, 0.5, and 1.

TABLE 20 F: molecular Sample Mn Mw Mz Mw/Mn weight A 2,968 29,017 96,6539.78 −1.00 B 1,453 32,145 107,283 22.12 −0.50 C 4,035 32,794 105,3788.13 0.00 D 10,471 41,001 112,471 3.92 0.50 E 2,306 40,523 130,662 17.571.00

FIG. 8 shows the layout of the five general levels of molecular weightin with designed unit values (F: molecular weight) of −1, −0.5, 0, 0.5,and 1, and the forty (40) groups of runs in this design.

A fully deployed DOE comprised 153 runs yielding laminated samples onwhich the peel strength was measured and then correlated to themolecular weight. Moreover, the runs were used in statistical analysisto define the optimized formulation.

The results of the evaluation of the peel strength performance foradhesive compositions prepared using ethylene-propylene copolymers ofvarious molecular weight distributions are shown in FIG. 9.

Polymer samples with molecular weight codes of −1, 0 and 1 correspondingto polydispersibility index of 8 to 18 provided a peel strength above160 g/25 mm. The highest peel was obtained for a polymer sample with apolydispersibility index of 18.

When Regalite® R1090 hydrocarbon resin was used with the inventive lowmolecular weight copolymer, the optimum formula was defined for acomposition that does not contain mineral oil. In this case, theperformance of the hot melt adhesives based on the inventive copolymerwas independent of molecular weight.

The values of the peel strength as a function of the polymer content inthe various formulations are shown FIG. 10.

Details on the optimum composition of the hot melt adhesive is providedin Table 21 below.

TABLE 21 BATCH MATERIAL Wt. % WEIGHT (lbs.) Inventive Low MolecularWeight 52.700 527 Copolymer Regalite ® R1090 hydrocarbon resin 45.000450 Sasol ® H-1 wax 2.000 20 Irganox ® 1010 antioxidant 0.295 2.95Eastobrite ® OB-1 optical brightener 0.005 0.05 TOTAL 100.00 1000.00Evaluations of Adhesive Peel Bond Strength

Each adhesive was applied between a polyethylene film and a nonwovenfabric to make laminates. The laminates were then debonded using atensile tester and the force applied to separate the plies was measuredas peel bond strength. The details for applying the adhesive onto thesubstrates, making laminates, and measuring the peel strength areprovided below.

The adhesives were evaluated using a Nordson CTL 4600 Series Hot MeltCoater (Nordson Corporation, 11475 Lakefield Drive, Duluth, Ga. 30097,USA) equipped with a Nordson adhesive applicator. The applicator wasconnected, through an insulated hose, to an adhesive melting tank of theNordson ProBlue 50 Melter. The overall operation of the machine andadhesive delivery were processed through an Allen Bradley PanelView 5and a Siemens Simatic controllers, all using Nordson-customizedproprietary software.

Two categories of applicators were used. They encompass NordsonUniversal Modules on which four spray nozzles were mounted and NordsonSlot Die systems.

Two groups of spray nozzles, operating in continuous and intermittentmodes, respectively, were selected for the evaluations of the hot meltadhesives. The continuous spray nozzles encompassed Universal SignatureStandard (model 1072290) and Universal Signature Low Flow (model1095242). The nozzles for intermittent spray process comprised UniversalSignature Standard Intermittent (model 1088478A) and Universal SignatureLow Flow Intermittent (model 1088478). The dual operation spraynozzle—continuous and intermittent—Universal Summit 3 holes (model1033006) was also used.

The slot die systems included continuous (model 784088) and intermittent(model C2501789897) applicators.

The samples for peel strength evaluation were made by laminating afive-inch wide polyethylene film to a five-inch wide nonwoven fabricusing liquid hot melt adhesives of interest.

The polyethylene film was Clopay Microflex® Film, DH284 PE White 360,0.001″×5″ (a 1-mil thick white film), supplied by Clopay PlasticProducts Company, 531 East Fourth street, Augusta, Ky. The nonwoven wasUnipro® 45, a 15 g/m² (or 0.45 oz./yd²) spunbond polypropylene fabricdistributed by Midwest Filtration, 9775 International Boulevard,Cincinnati, Ohio

The solid adhesive was placed in a ProBlue melting tank and heated tothe target temperature to obtain a homogeneous liquid. The chosen targettemperatures were 120, 130, 140, 145, 150, and 160° C. The moltenadhesive was then pumped from the melting tank, through a heatedinsulated hose, to the spray module and nozzles, to deposit onto thepolyethylene film, moving at a speed of 400 or 600 m/min, an amount ofadhesive corresponding to a preselected add-on (1, 2, or 3 g/m²). Thenonwoven fabric, moving at the same speed as the polyethylene film, wasthen brought in contact with the polyethylene film, on the side that hadthe adhesive layer. The assembly was run through an S-wrap and acompression nip (or gap) between two (steel and rubber) rolls to contactthe substrates and bond them to each other. The laminate thus createdwas wound into a roll. At the end of the process, the machine wasstopped and specimens (in the form of bundles of short laminates ortabs) were collected from the roll by slicing, and saved for subsequentpeel strength evaluations.

The process was repeated for each adhesive and set of operatingconditions to generate various samples for peel strength evaluation.

The coater rewinder pack roll and the compression nip were operated at agauge pressure of 21 to 25 and 30 psi, respectively.

The bond strength between layers in the laminates for the varioussamples was measured as 180 degrees peel strength using universaltensile testers at a cross-head speed of 30 mm/min. The instrumentsencompassed a Chem Instruments Adhesion Release Tester AR-1000 equippedwith a 22.24 N (5 lbf) load cell, and a MTS Criterion Universal TensileTester model C43-104E on which a 500 N (112 lbf) load cell (model LPB502) was mounted. The MTS instrument was controlled by Test Works 4(version 4.12D) software installed on a HP computer system.

The test was conducted in the following manner. Samples made of severallaminates of each sample were conditioned in accordance with the type ofinformation to collect. The instant peel strength was measured within 5minutes of the laminates preparation, with no special sampleconditioning, the 24-hour and 1-month peel strengths were evaluated onsamples conditioned at 50% RH and 25° C. for 24 hours and 1 month,respectively. Two sets of samples were conditioned at 38° C. (for 4hours) and 49° C. (for 2 weeks) to generate the 4-hour and 2-week peelstrength data, respectively.

After conditioning, one extremity of the laminate was disassembled bypeeling to separate the two plies on a length of about 50 mm. Then, eachply's end was clamped in the two tester grips initially positioned at 75mm of each other. The laminate was then peeled on a length of 100 mm ata speed of 300 mm/min and the instant force applied to separate theplies was continuously measured, stored in the computer and thenprocessed to determine the average value of the readings. Six individualspecimens taken from each sample were thus tested and the average valueof all the peel bond strengths for the six specimens was calculated andreported as the peel strength for the sample.

Comparative Data on Peel Strength Compared for Examples 14-16

The graphs in FIGS. 11-20 show comparative peel strength data forlaminates bonded with Comparative Aerafin™ 180 copolymer, InventiveCopolymer 60/40, and Inventive Copolymer 52/45, and a commercialrubber-based hot melt adhesive. The peel strengths are related tolaminates exposed to various conditioning environments as describedabove in the procedures for peel strength measurement.

Hot melt adhesives prepared using the inventive low molecular weightpropylene-ethylene copolymer yielded high peel strength laminates acrossthe whole range of application temperature. Also, the peel value wasrelatively constant over the wide range of spray temperature. Theconsistency of the peel strength provides a great commercial advantagefor the user of the hot melt based on the inventive low molecular weightpropylene-ethylene copolymer since the adhesive provided a constant highquality finished goods when laminated with the adhesive of thisinvention regardless of the temperature used during the manufacturingprocess of the goods.

At the same add-on, the inventive low molecular weightpropylene-ethylene copolymer offers a peel strength that issignificantly higher than the peel strength obtained with ComparativeAerafin® 180 copolymer. Moreover, at a given application temperaturebelow 152° C., hot melt adhesives based on the inventive low molecularweight propylene-ethylene copolymer provide the possibility for savingsfor the user since only a small amount of adhesive can be applied toyield a peel strength similar to that obtained when using a hot meltadhesive based on the Comparative Aerafin® 180 copolymer and a higheradd-on.

Example 17

Adhesives were produced in aluminum cans using mechanical agitation witha paddle-type agitator controlled by a variable speed motor with a heatmantle set at 177° C. The propylene-ethylene copolymer(s), polypropylene(co)polymer(s), tackifier resins, waxes, and antioxidant were introducedinto the can and heated to 177° C. under a nitrogen blanket. In somecases, oil was also added along with the resin and/or wax or in place ofresin and/or wax. This mixture was agitated for 30 minutes until it wascompletely homogenous. After thorough mixing, the adhesive was pouredonto a silicone or silicone-coated surface and allowed to cool. Theadhesives were produced with various additives, including: Eastotac®H130W, hydrogenated hydrocarbon resin (Eastman); Sasolwax™ H1,Fischer-Tropsch wax (Sasol Chemical Industries Limited, South Africa);Be Square 195 Microcrystalline Wax (Baker Hughes, Inc., Sugar Land,Tex.); EPOLENE™ N-15, polypropylene homopolymer wax (Westlake Polymers,LLC, Houston, Tex.); Achieve™ 6936, polypropylene homopolymer,metallocene based (Exxon-Mobil, Houston, Tex.); Vistamax™ 8880 isotacticpropylene-ethylene copolymer, metallocene catalyzed, semi-crystalline(Exxon-Mobil); A-C® 596, propylene maleic anhydride copolymer wax(Honeywell International, Inc., Morristown, N.J.).

Viscosity of the adhesives was measured using a standard Brookfieldviscometer equipped with a Thermosel. Measurements were taken 30 minutesafter the composition was molten.

100 g peel was performed using standard US PAFT (peel adhesion failuretemperature) method using 60# Kraft paper. Laminated section was 1″ by1″ by 10 mil of adhesive thickness.

500 g shear was performed in accordance with ASTM D4498-SAFT (shearadhesion failure temperature) method using 60# Kraft paper. Thelaminated section was 1″ by 1″ by 10 mil adhesive thickness.

Open time was evaluated in accordance with ASTM D4497.

Bonding tests to corrugated cardboard were done by making the bonds byhand then allowing the bonds to stand at room temperature for at least12 hours. The bonds were then placed into the specified temperatureconditioning chamber and allowed to stand for at least 24 hours. Thebonds were evaluated by ripping them apart at the conditioningtemperature and reading the percentage of adhesive area covered by paperfiber. Refrigerator temperature was 4° C.

TABLES 22 and 23 provide the formulations for each adhesive and thevarious measured properties. It should be noted that all adhesivescomprised 0.5 weight percent of Irganox 1010.

TABLE 22 Materials F1 F2 F4 F5 F6 F7 F8 Aerafin ® 17 30% 60% 70% 55% 55%55% 50% Aerafin ® 20 0 0 0 0 0 0 180 Eastotac ® 30 25 0 30 30 30 30H130W Sasolwax ™ 20 0 0 0 0 0 0 H1 Be Square  0 15 0 0 0 0 0 195Epolene ™ — 0 30 15 0 0 15 N-15 Achieve ™ — 0 0 0 15 0 0 6936 Vistamax ™ 0 0 0 0 0 15 0 8880 A-C ® 596  0 0 0 0 0 0 5 Adhesive Opaque OpaqueVery Clear Clear Very clear Clear film Brittle Brittle brittle FlexibleFlexible Shiny Flexible Description Friable Friable Very Tough ToughVery Tough Stiff Stiff stiff flexible Soft

TABLE 23 Materials F5 F6 F7 F8 Target value Aerafin ® 17 55% 55% 55% 50%— Eastotac ® H130W 30 30  30  30  — Epolene ™ N-15 15 0 0 15  —Achieve ™ 6936 0 15  0 0 — Vistamax ™ 8880 0 0 15  0 — A-C ® 596 wax 0 00 5 — Adhesive Properties Adhesive Film Description Clear Clear Veryclear Clear Flexible Flexible Flexible Shiny Flexible Tough tough toughVery flexible Tough Soft Viscosity at 177° C. 1273 cps 2384 cps 1336 cps1142 cps 1000 cps RT Bonding* to Corrugated Excellent ExcellentExcellent Excellent Excellent Cardboard Refrigerator (4° C.) bonding* toMarginal Marginal Good Good Good Corrugated Cardboard 100 g Peel (PAFT,ASTM)  45° C. (113° F.)  42° C. (108° F.) 42° C. (108° F.)  53° C. (128°F.) 66° C. (151° F.) 500 g Shear (SAFT, ASTM) 120° C. (248° F.) 126° C.(259° F.) 93° C. (199° F.) 125° C. (257° F.) 94° C. (201° F.) Speed ofSet** 1.5 3 5 (very slow) 2 1 (Fast) *Excellent = 80-100% fiber tear;Good = 50-79% fiber tear; Marginal = 20-49% fiber tear; Fail = 0-19%fiber tear. **Speed 1-5, with 1 = fast.

As shown in TABLES 22 and 23, various adhesive compositions containingthe inventive low molecular weight polymer Aerafin® 17 and the inventivehigh molecular weight polymer Aerafin® 180 with various waxes andpolymers were produced. The “Target” adhesive values were from acommercially available adhesive based on ethylene-octene copolymerproduced using a metallocene catalyst (“mPE”) (HB Fuller AdvantraPHC9256).

Samples 1 and 2 illustrate that the use of waxes typically used in EVAand ethylene-octene (metallocene catalyzed, mPE) packaging adhesives, inthe amounts typically used, resulted in stiff, brittle, and friablecompositions with little mechanical integrity. Samples 5-8 producedclear, flexible compositions with excellent room temperature adhesion tocorrugated cardboard. Unexpectedly, samples 5, 6 and 8 had 27.6%, 34%and 33% higher Shear adhesion failure temperature (SAFT) performance,respectively, than the target value. Surprisingly, the high SAFT valueswere combined with set times acceptable on commercial packaging lines.

Additionally, the flexibility and elasticity of the formulation,particularly F7 comprising Aerafin® polymer and Vistamaxx™ 8880 polymer,an isotactic metallocene-catalyzed propylene/ethylene copolymer,indicates possible advantages in elastic attachment adhesives fordisposable sanitary hygiene articles such as diapers, feminine pads andadult incontinence articles.

Example 18

Inventive hot melt adhesives for packaging applications were producedusing the process described in Example 17; the composition, in weightpercent, and properties of the adhesives are listed in TABLE 24. Theadhesives were produced with various polypropylene additives, includingLicocene™ PP 6102, a metallocene-catalyzed polypropylene polymer waxwith high crystallinity; Licocene™ PP 1302, a metallocene-catalyzedpropylene-ethylene polymer wax with low crystallinity, both availablefrom Clariant International Ltd. (Muttenz, Switzerland); Epolene® N-15(Westlake) and A-C® 596, a propylene maleic anhydride copolymer wax(Honeywell). A second Commercial Adhesive, FT6, based on ethylene-octenepolymer that is metallocene-catalyzed (mPE), was tested for comparison.

Compared to commercial comparative adhesive FT6, samples FT2 and FT3comprising the inventive propylene-ethylene copolymer and apolypropylene polymer/wax unexpectedly exhibited the combination ofviscosity at 177° C. about 800-1800 cp with over 34% and 19% higher SAFTvalues and improved adhesion (percent fiber tear) at −7° C. and −15° C.

TABLE 24 Materials IA FT2 IA FT3 IA FT4 CA FT6 Aerafin ™ 17 40 40 37 —Aerafin ™ 180 10 10 8 — Eastotac ™ H130W 30 30 35 — Licocene ™ PP 6102 015 0 — Licocene ™ PP 1302 0 0 5 — Epolene ™ N-15 15 0 10 — A-C ™ 596 5 55 — Adhesive properties RBSP (° C.) 150 132 148 111 Viscosity at 177° C.(cP) 1660 1098 1295 1000 100 g Peel (PAFT, ASTM) 68 47 61 67 500 g Shear(SAFT, ASTM) 129 115 122 96 OPEN TIME (sec) 30 >60 >60 10 SET TIME (sec)15 25 25 10 Fiber tear at room temperature (%) >80 >80 >80 >80 Fibertear at −7° C. (%) >80 >80 >50 >50 Fiber tear at −15° C. (%) >80 >80 <50<50

Example 19

Assembly adhesives AF3, AF4 and AF5 were prepared according to theweight percent given in TABLE 27 by adding the tackifier, oil and anantioxidant to a metallic container and heating the mixture to 180° C.The mixture was melted, agitated, and then the inventivepropylene-ethylene copolymer Aerafin® 180, Vestoplast™ 703, apropylene-ethylene-butene terpolymer with short open time, Vestoplast™792, a propylene-ethylene-butene terpolymer with long open time, and/orEastoflex™ polymers were added. The mixture was continuously mixed untilit was completely melted. Degassing was performed when necessary toremove air bubbles trapped in the adhesive. Brookfield viscosity andring and ball softening point (RBSP) were measured as previouslydescribed. It should be noted that the compositional components recitedin TABLE 27 are based on weight percentage and that all components addup to 100 percent; however, this does not include the 0.3 percent ofantioxidant (Irganox® 1010), which was added after all other componentswere combined. The weight percentage for the antioxidant was based offthe combined weight percentage of the other components.

The adhesives were manually coated as pressure sensitive adhesives at180° C. using a doctor blade with a 50 micron gap onto one mil PET film.The adhesive-coated PET was applied to stainless steel (SS) coupons and180° peel strength was tested following standard method PSTC-101 usingan Instron 5543 at 300 mm/min.

The open time of the adhesive was determined manually by pouringadhesive at 180° C. onto nonwoven substrate WYPAL™ X60 fromKimberly-Clark in a bead line approximately 3 g/inch, applying a secondpiece of nonwoven to the bead of adhesive with finger pressure, andslowly peeling the second nonwoven until the adhesive did not adhere tothe second nonwoven substrate, then recording this time as the opentime.

TABLE 27 Component AF3 AF4 AF5 — Vestoplast ™ 703 40 20 0 — Vestoplast ™792 15 15 0 — propylene-ethylene copolymer 0 15 38 — Aerafin ™ 180Eastoflex ™ 1023 0 0 9.5 — Regalite ™ R1100 40 40 43 — KN4010 oil 10 109.5 — Adhesive Test AF3 AF4 AF5 Target Viscosity at 180° C. (cP) 21123150 2250 1500-3000 RBSP (° C.) 102 98 123 100-130 180° peel strength,SS (N/25 mm) 60 61 41 unknown Open time, nonwoven to nonwoven >10 >10 Notest >10 (min)

Example 20

Adhesives were produced and tested as previously described in EXAMPLE17, and the compositions and adhesive properties are presented in Tables28 and 29. Commercial packaging adhesive (“Com. D”) based on anethylene-octene copolymer (mPE) was tested for comparison. Inventiveadhesives AT2, AT3 and AT7 demonstrate the surprising increase in lowtemperature adhesion, compared to AT1 and Com. D, when Aerafin™ 180 andthe Inventive Low Molecular Weight Copolymer are used together withvarious resins and waxes, as evidenced by percent fiber tear oncorrugated cardboard at −18° C. Inventive adhesives AT5 and AT6 havepolymer loading of 70 weight percent or higher with less than 15 weightpercent tackifying resin, but surprisingly also have 80-100% fiber tear(low temperature adhesion). Additionally, it is surprising thatInventive adhesives AT2 through AT7 have RBSP and SAFT values higherthan Com. D in combination with the superior low temperature adhesion.The combinations of propylene waxes and ethylene waxes illustrate theability to obtain set times close to Com. D while improving lowtemperature adhesion, increasing SAFT, and maintaining 177° C.Brookfield viscosity of the adhesive.

TABLE 28 Materials AT1 AT2 AT3 AT4 AT5 AT6 AT7 Inventive Low 0 40 40 3776 70 40 Molecular Weight Copolymer propylene-ethylene 40 10 10 8 0 0 15copolymer Aerafin ™ 180 Eastotac ™ H130W 0 30 30 35 0 10 10 Regalite ™R1100 0 0 0 0 14 0 0 Regalite ™ R1090 30 0 0 0 0 0 0 Polywax ™ 3000 30 00 0 6 0 0 Licocene ™ PP6102 0 0 15 0 0 20 0 Licocene ™ PP1302 0 0 0 5 00 0 Epolene ™ N-15 0 15 0 10 0 0 0 Polywax ™ 850 0 0 0 0 0 0 20Polywax ™ 500 0 0 0 0 0 0 10 Bareco ™ 4040 0 0 0 0 0 0 5 Sasolwax ™ H-10 0 0 0 2 0 0 A-C ™ 596 0 5 5 5 2 0 0

TABLE 29 Adhesive Properties AT1 AT2 AT3 AT4 AT5 AT6 AT7 Com. D RBSP (°C.) 125 150 132 148 125 138 115 111 Viscosity at 177° C. 1715 1660 10981295 1200 1075  800 1000 (cP) PAFT JAI, 300 g, 41 65 59 60 34 No test Notest 68 0.5° C./min (° C.) SAFT JAI, 500 g 80 113 108 105 99 No test Notest 87 0.5° C./min (° C.) Open time (sec) 10 30 >60 >60 30  35  15 10Set time (sec) 10 15 25 25 15  15  30 10 = fast 50° C. holding 12 106 3545 11 No test No test 1200 power, JAI peel, 300 g (min) Fiber tear at−18° C. >50 >80 >80 >50 >80 100 100 <50 (%)

Example 21

For this example, general packaging adhesives were produced thatcomprised 0 to 15 weight percent of Aerafin® 180 from Eastman Chemical,25 to 40 weight percent of a metallocene-catalyzed polyethylene (“mPE”),40 weight percent of a tackifier resin (Eastotax H130W), 20 weightpercent of a wax (Sasolwax H1), and 0.3 weight percent of anantioxidant. The adhesives were prepared by first adding the tackifier,wax, and antioxidant to a metallic container and heating the mixture to180° C. with the aid of an agitator. The mixture was melted, agitated,and then the Aerafin® 180 and polyethylene were added. The mixture wascontinuously mixed until it was completely melted. Degassing wasperformed when necessary to remove air bubbles trapped in the adhesive.

After forming the adhesives, the open time/set time (OT/ST), lowtemperature fiber tear (LTFT) at −15° C. and −25° C., holding power at50° C. and 60° C., and peel adhesive failure temperature (PAFT) weremeasured and evaluated for each formed adhesive. The holding power andLTFT were measured in accordance with the previously-described tests.

The PAFT was tested according to JAI-7—Method B, which is described asfollows. The PAFT test occurred under the ramp rate of 0.5° C./minute.For the PAFT test, the glued carton sample was cured overnight at theroom temperature, which normally was about +/−20° C. to 23° C., beforebeing hanged in the shear bank oven in the peel mode. A weight of 300gram was hung under the glued sample. For each sample, the failure timewas recorded in minutes and the failure temperature was calculated usingthe equation (Fail Temp =40° C. +0.5° C./min*(minutes)). A minimum of 8specimens were needed for this test. The following lays out theparameters for the PAFT testing.

Criteria Unit Condition Specimen size mm 25 × 60 Application temperatureCelsius 180 ± 2  Open time s 2 Set time s 2 Line speed m/min 15 BondingPressure kgf 1.2 (0.08 kgf per cm²) Coat weight g/m   3 ± 0.09 Hangweight g 300

The compositions of each tested adhesive, along with their measuredPAFT, LTFT, open time, set time, cloud points, and holding powers at 50°C. and 60° C. are provided, below, in TABLE 30.

TABLE 30 Holding Holding Power Power Open Set Cloud PAFT LTFT % LTFT %50° C. 60° C. Time Time Point Adhesive Formulation (° C.) (−15° C.)(−25° C.) (min) (min) (s) (s) (° C.) Commercial grade from 71 98 — 42012 15 2 — key HMA formulator F0 (control formulation): 78 98 95 1144 2513 1 120 Affinity GA1950/Eastotac H130W/H1wax = 40/40/20 F1: Aerafin180/Affinity 82 92 84 1498 58 15 1 — GA1950/Eastotac H130W/H1wax =5/35/40/20 F2: Aerafin 180/Affinity 82 93 95 997 52 15 1 —GA1950/Eastotac H130W/H1wax = 10/30/40/20 F3: Aerafin 180/Affinity 79 8159 413 33 13 1 — GA1950/Eastotac H130W/H1wax = 15/25/40/20 F4: Aerafin180/Eastotac — — — — — — — 152 H130W/H1 wax = 40/40/20

It can be seen above from TABLE 30 that when 5 weight percent ofAerafin® 180 was added to the formulation to replace Affinity GA1950,the resultant hot melt adhesive illustrated excellent holding power at50° C. and 60° C. compared to commercial grade and control formulation.In addition, the measured LTFT, PAFT and OT/ST of the adhesive werecomparable. When 10 weight percent Aerafin® 180 was added to theformulation, the obtained holding power at 50° C. was slightly decreasedcompared with F0 and F1, but the resulting holding power at 60° C. wasstill twice as high as that of control formulation and four times higherthan that of the commercial grade hot melt adhesive; however, as thedosage of Aerafin® 180 further increased, a decrease in holding power at50° C. and 60° C. was observed. The resulting holding power at 60° C.was still much higher than the commercial grade, suggesting animprovement in holding power at high temperature due to the presence ofAerafin® 180 in the formulation.

The observed decrease in holding power as the dosage of Aerafin® 180increased might have resulted from relatively poor compatibility betweenAerafin® 180 and Sasolwax H1. The compatibility between Aerafin® 180 andSasolwax H1 may be relatively poor compared with that of mPE andSasolwax H1, as shown in cloud point value (TABLE 30). It can be seenfrom TABLE 30 that the formulation containing Aerafin® 180 (F4) had acloud point of 152° C., while the one containing mPE (F0) had a cloudpoint of 120° C. It is well known that the lower the cloud point, thebetter compatibility between polymer and wax. Therefore, the relativelypoor compatibility between Aerafin® 180 and Sasolwax H1 led to areduction in holding power as the dosage of Aerafin® 180 in theformulation increased.

Furthermore, the resulting improvement in high temperature holding powerof the formulations containing Aerafin® 180 might be attributed to therelatively high ring and ball softening points (“RBSP”) of Aerafin® 180(118° C. vs. 93° C. of mPE). It is generally accepted that high RBSP canbe responsible for high heat resistance, leading to attractive hightemperature holding power. It can be seen that at 5 weight percent ofAerafin® 180, both holding power at 50° C. and 60° C. are higher thanthose of commercial HMA and the control formulation. However, as thedosage of Aerafin® 180 further increased, a decrease in holding power at50° C. and 60° C. was observed, and the reduction in holding power at50° C. was more significant compared with the reduction in holding powerat 60° C., as discussed previously. The decrease in holding power asdosage of Aerafin® 180 increased might be due to relatively poorcompatibility between Aerafin® 180 and Sasolwax H1. It is well knownthat higher temperature favors a more compatible system; therefore,Aerafin® 180 and Sasolwax H1 are more compatible at 60° C. than at 50°C. At 50° C., the compatibility issue is more dominant than thecontribution of the higher RBSP of Aerafin® 180, leading to a loweringin holding power; while at 60° C., the resulting compatibility issue isless significant, resulting in less reduction in holding power.

Example 22

Adhesive samples were prepared using techniques known in the art. Thecomponents of each adhesive sample and their various properties arelisted, below, in TABLES 31-34. An exemplary procedure involved placingthe components in a glass mixing kettle equipped with a stirrer at 170rpm and raising the temperature to from about 150° C. to 180° C.,depending on the softening points of the components. Stirring wasinitiated when the mixture became molten, and heating and mixing werecontinued at 180° C. for one hour until a smooth homogeneous mass wasobtained. The formulations were prepared in a 500 mL reactor undernitrogen atmosphere. About 150 grams of an adhesive were prepared undernitrogen. The adhesives samples were subjected to various tests tomeasure their adhesive-based properties.

The viscosity of the samples was measured with a Brookfield viscometer(Model DV-I). Spindle 21 and 8 grams of adhesive were used for themeasurements. The sample was heated until the desired temperature andallowed to equilibrate under sheer for 20 minutes.

The PAFT and holding power tests were performed according to the methodsutilized in Example 21.

The ring and ball softening point was determined with Herzog HRB754equipment. The adhesive rings were placed in glycerin with balls layingon top of the adhesive ring. The glycerin was heated up continuously andthe temperature, at which the ring fell through the adhesive, wasrecorded.

A bond tester was used to determine the set time. A 7.5×7.5 cm cartonwas placed on a 15×15 cm coated carton and by varying pressing times,the fiber tear and traction force were determined. The flutes wereplaced in cross direction, the adhesive was coated at 180° C. and apressing force of 85N was applied. The set time was determined by takingthe first point when 100% fiber tear was reached.

Five flasks each containing 90 g of adhesive were prepared and placed inan oven at 175° C. and after each day (24 h, 48 h, 72 h and 96h) thecolor and viscosity were determined with the Gardner Color method andBrookfield viscometer. The Gardner color was measured in a Dr. LangeLico 400+apparatus. The instrument was calibrated using toluene.

TABLE 31 Sample 1 2 3 4 5 6 7 8 Eastoflex ® E1060 100 35 52 52 45.5 45.535.75 35.75 Aerafin ® 17 65 28 28 24.5 24.5 19.25 19.25 Regalite R112520 30 25 40 40 Eastotac H130W 20 Licocene PP6102 5 5 Sasolwax H1 5 RBSP(° C.) 143 141 138 138 135 137 133 127 Viscosity at 180 (° C.) 2300 45003125 3491 2558 2366 1585 1402 PAFT (° C.) 26 40 64 58 65 63 71 81Holding power at 50° C. (minutes) 0 5 17 9 13 16 60 319 % Fiber tear at−15° C. 5 70 70 80 70 50 0 0

As shown above in TABLE 31, Samples 1 and 2 comprised 100 weight percentof polymer (Eastoflex® E1060 and Aerafin® 17). Sample 2 showed improvedlow temperature adhesion and PAFT obtained from the additional polymer.Samples 3 and 4 comprised 80 weight percent of polymer; Samples 5 and 6comprised 70 weight percent of polymer; and Samples 7 and 8 comprised 55weight percent of polymer. Sample 6 exhibited low viscosity at 180° C.with a surprisingly long hold power at 50° C.

TABLE 32 Sample 9 10 11 12 13 14 15 16 17 Eastoflex ® E1060 45.5 45.545.5 45.5 45.5 45.5 45.5 45.5 45.5 Aerafin ® 17 24.5 24.5 24.5 24.5 24.524.5 24.5 24.5 24.5 Regalite R1125 25 25 25 25 25 25 25 25 25 EpoleneN15 5 Epolene E43 5 Epolene C13 5 Epolene N14P 5 Epolene N21 5 LicocenePP6102 5 Paraffin 66-69 5 Sasolwax 080 5 Sasolwax H1 5 RBSP (° C.) 145143 137 134 134 137 135 135 132 Viscosity at 180 (° C.) 2575 2454 19202320 2420 2366 2033 2000 2133 PAFT (° C.) 61 94 62 69 70 63 61 69 74Holding power at 50° C. 16 220 31 29 50 16 24 52 81 (minutes) % Fibertear at −15° C. 70 100 35 30 40 50 20 10 10

As shown above in TABLE 32, Samples 9 through 17 comprised 70 weightpercent of polymer. Sample 10 exhibited an unexpected and desirablebalance of high temperature resistance indicated by PAFT and holdingpower at 50° C. with low temperature fiber tear performance.

TABLE 33 18 19 20 21 22 23 Com. A Com. B Aerafin ® 17 45.5 43.55 43.5543.55 43.55 Eastoflex ® E1060 24.5 23.45 23.45 23.45 23.45 Aerafin ® 18010 AFFINITY GA ™ 1950 30 Eastotac H130W 40 Foralyn 90 rosin ester 25 2525 25 25 Epolene N15 5 5 Epolene N21 5 5 5 Sasolwax H1 3 3 20 LicocenePE4201 3 3 RBSP (° C.) 134 132 133 146 146 111 106 96 Viscosity at 180(° C.) 1720 1854 1800 2000 1900 1290 813 676 PAFT (° C.) 65 65 66 88 6372 68 56 Holding power at 50° C. 54 48 32 38 39 1440 154 12 (minutes) %Fiber tear at −15° C. 50 25 45 25 15 100 15 35 Set time (sec) 18 13 1711 10 11 16

As shown above in TABLE 33, Samples 18 through 22 comprised 67 weightpercent of polymer. Sample 18 had a higher PAFT, longer hold power at50° C., and faster set time than Commercial Adhesive B (“Com. B”).Sample 23 comprised 40 weight percent of polymer and exhibited asurprisingly long hold power at 50° C. Commercial Adhesive A (“Com. A”)was also presented as a comparison for the produced adhesives.

TABLE 34 Com. 24 25 26 27 28 29 C Aerafin ® 180  60  59  55  40  55  40Eastoflex ® P1023   1   5  20 Eastoflex ® E1003   5  20 Regalite R1090 30  30  30  30  30  30 Primol 352 mineral  10  10  10  10  10  10 oilViscosity @ 3387 3937 3470 2330 3070 1490 2500 180° C. (mPa · s) RBSP (°C.)  103  103  112  132  104  107  100

As shown above in TABLE 34, Samples 24 through 29 comprised 60 weightpercent of polymer and illustrate that the use of an additional polymerobtained a more desirable viscosity and RBSP for adhesives, such asthose used in product assembly. Another commercial adhesive (“Com. C”)was provided for comparison purposes.

What is claimed is:
 1. An adhesive comprising at least onepropylene-ethylene copolymer and at least one polyolefin, wherein saidat least one propylene-ethylene copolymer comprises at least 10 weightpercent of ethylene, a softening point of at least 99° C., and a glasstransition temperature (Tg) in the range of −60 to 20° C.
 2. Theadhesive of claim 1, wherein said at least one polyolefin is selectedfrom the group consisting of amorphous polyolefins, semi-crystallinepolyolefins, alpha-polyolefins, reactor-ready polyolefins,metallocene-catalyzed polyolefin polymers and elastomers, reactor-madethermoplastic polyolefin elastomers, olefin block copolymers,thermoplastic polyolefins, atactic polypropylene, polyethylenes,ethylene-propylene polymers, propylene-hexene polymers, ethylene-butenepolymers, ethylene-octene polymers, propylene-butene polymers,propylene-octene polymers, metallocene-catalyzed polypropylene polymers,metallocene-catalyzed polyethylene polymers, propylene-based terpolymersincluding ethylene-propylene-butylene terpolymers, copolymers producedfrom propylene and linear or branched C4-C10alpha-olefin monomers,copolymers produced from ethylene and linear or branched C4-C10alpha-olefin monomers, and functionalized polyolefins.
 3. The adhesiveof claim 1, wherein said at least one propylene-ethylene copolymercomprises 12 to 40 weight percent of ethylene.
 4. The adhesive of claim1, wherein said at least one propylene-ethylene copolymer comprises asoftening point in the range of 105 to 145° C.
 5. The adhesive of claim1, wherein said at least one propylene-ethylene copolymer comprises aneedle penetration in the range of 8 to 75 dmm as measured according toASTM D5.
 6. The adhesive of claim 1, wherein said at least onepropylene-ethylene copolymer comprises a crystallinity of less than 30percent as measured using DSC according to ASTM E 794-85 and a numberaverage molecular weight (Mn) of less than 25,000 as determined by gelpermeation chromatography.
 7. The adhesive of claim 1, wherein said atleast one propylene-ethylene copolymer comprises a Brookfield viscosityat 190° C. of less than 30,000 cps as measured according to ASTM D3236.8. The adhesive of claim 1, wherein said adhesive comprises: (a) 5 to 95weight percent of said at least one propylene-ethylene copolymer; (b) 5to 90 weight percent of said at least one polyolefin; (c) not more than70 weight percent of at least one tackifier; (d) not more than 20 weightpercent of a processing oil; and (e) not more than 30 weight percent ofat least one wax.
 9. The adhesive of claim 1, wherein said adhesive hasBrookfield viscosity at 177° C. in the range of 800-5000 cP and at leastone of the following: (a) a greater holding power at 50° C.; (b) a lowerviscosity at 177° C.; or (c) a higher peel adhesion failure temperature,than the same composition without the at least one propylene-ethylenecopolymer and the at least one polyolefin.
 10. The adhesive of claim 1,wherein said adhesive comprises: (a) 10 to 70 weight percent of said atleast one propylene-ethylene copolymer; (b) 5 to 55 weight percent ofsaid at least one polyolefin; (c) not more than 70 weight percent of atleast one tackifier; (d) not more than 20 weight percent of a processingoil; and (e) not more than 20 weight percent of at least one wax.
 11. Anadhesive comprising at least one propylene-ethylene copolymer and atleast one polyolefin, wherein said at least one propylene-ethylenecopolymer comprises a polydispersity of 3 to
 25. 12. The adhesive ofclaim 11, wherein said at least one polyolefin is selected from thegroup consisting of amorphous polyolefins, semi-crystalline polyolefins,alpha-polyolefins, reactor-ready polyolefins, metallocene-catalyzedpolyolefin polymers and elastomers, reactor-made thermoplasticpolyolefin elastomers, olefin block copolymers, thermoplasticpolyolefins, atactic polypropylene, polyethylenes, ethylene-propylenepolymers, propylene-hexene polymers, ethylene-butene polymers,ethylene-octene polymers, propylene-butene polymers, propylene-octenepolymers, metallocene-catalyzed polypropylene polymers,metallocene-catalyzed polyethylene polymers, propylene-based terpolymersincluding ethylene-propylene-butylene terpolymers, copolymers producedfrom propylene and linear or branched C4-C10alpha-olefin monomers,copolymers produced from ethylene and linear or branched C4-C10alpha-olefin monomers, and functionalized polyolefins.
 13. The adhesiveof claim 11, wherein said at least one propylene-ethylene copolymercomprises 10 to 40 weight percent of ethylene and a softening point inthe range of 99 to 145° C.
 14. The adhesive of claim 12, wherein said atleast one polyolefin comprises an amorphous polyolefin having a heat offusion of less than 25 J/g and/or wherein said at least onepropylene-ethylene copolymer comprises a Brookfield viscosity at 190° C.of less than 30,000 cps as measured according to ASTM D3236.
 15. Theadhesive of claim 11, wherein said at least one propylene-ethylenecopolymer comprises a crystallinity of less than 30 percent as measuredusing DSC according to ASTM E 794-85, and a number average molecularweight (Mn) of less than 20,000 as determined by gel permeationchromatograph.
 16. The adhesive of claim 11, wherein said at least onepropylene-ethylene copolymer comprises a needle penetration in the rangeof 8 to 75 dmm as measured according to ASTM D5 and a melt temperaturein the range of 90° C. to 135° C.
 17. The adhesive of claim 11, whereinsaid adhesive comprises: (a) 5 to 95 weight percent of said at least onepropylene-ethylene copolymer; (b) 5 to 90 weight percent of said atleast one polyolefin; (c) not more than 70 weight percent of at leastone tackifier; (d) not more than 20 weight percent of a processing oil;and (e) not more than 20 weight percent of at least one wax.
 18. Theadhesive of claim 11, wherein said adhesive comprises: (a) 20 to 80weight percent of said at least one propylene-ethylene copolymer; (b) 1to 45 weight percent of said at least one polyolefin; (c) not more than70 weight percent of at least one tackifier; (d) not more than 20 weightpercent of a processing oil; and (e) not more than 20 weight percent ofat least one wax.
 19. An article comprising the adhesive of claim 1wherein said article is selected from the group consisting of adhesives,sealants, caulks, roofing membranes, waterproof membranes andunderlayments, carpet, laminates, laminated articles, tapes (e.g.,tamper evident tapes, water activated tapes, gummed tape, sealing tape,scrim reinforced tape, veneer tape, reinforced and non-reinforced gummedpaper tape, box makers tape, paper tape, packaging tape, HVAC duct tape,masking tape, invisible tape, electrical tape, gaffer tape, hockey tape,medical tape, etc.), labels (e.g., general purpose label, beveragelabel, freezer label, smart label, consumer electronics etc.), mastics,polymer blends, wire coatings, molded articles, heat seal coatings,disposable hygiene articles, insulating glass (IG) units, bridgedecking, water proofing membranes, waterproofing compounds,underlayments, cable flooding/filling compounds, sheet molded compounds,dough molded compounds, overmolded compounds, rubber compounds,polyester composites, glass composites, fiberglass reinforced plastics,wood-plastic composites, polyacrylic blended compounds, lost-waxprecision castings, investment casting wax compositions, candles,windows, films, gaskets, seals, o-rings, motor vehicle molded parts,motor vehicle extruded parts, clothing articles, rubberadditive/processing aids, and fibers.
 20. The adhesive of claim 11,wherein said adhesive has Brookfield viscosity at 177° C. in the rangeof 800-5000 cP and at least one of the following: (a) a greater holdingpower at 50° C.; (b) a higher peel adhesion failure temperature; (c) alower viscosity at 177° C.; or (d) a greater percent fiber tear at −15°C. on corrugated cardboard, than the same composition without the atleast one propylene-ethylene copolymer and the at least one polyolefin.